Horizontal Scroll View Line Drawing
public class HorizontalScrollView
extends FrameLayout
java.lang.Object | ||||
↳ | android.view.View | |||
↳ | android.view.ViewGroup | |||
↳ | android.widget.FrameLayout | |||
↳ | android.widget.HorizontalScrollView |
Layout container for a view hierarchy that can be scrolled by the user, allowing it to be larger than the physical display. A HorizontalScrollView is a FrameLayout
, meaning you should place one child in it containing the entire contents to scroll; this child may itself be a layout manager with a complex hierarchy of objects. A child that is often used is a LinearLayout
in a horizontal orientation, presenting a horizontal array of top-level items that the user can scroll through.
The TextView
class also takes care of its own scrolling, so does not require a HorizontalScrollView, but using the two together is possible to achieve the effect of a text view within a larger container.
HorizontalScrollView only supports horizontal scrolling. For vertical scrolling, use either ScrollView
or ListView
.
Summary
XML attributes | |
---|---|
android:fillViewport | Defines whether the scrollview should stretch its content to fill the viewport. |
Inherited XML attributes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
From class
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From class
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From class
|
Inherited constants | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
From class
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From class
|
Inherited fields | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
From class
|
Public constructors | |
---|---|
HorizontalScrollView(Context context) | |
HorizontalScrollView(Context context, AttributeSet attrs) | |
HorizontalScrollView(Context context, AttributeSet attrs, int defStyleAttr) | |
HorizontalScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) |
Public methods | |
---|---|
void | addView(View child, int index) Adds a child view. |
void | addView(View child) Adds a child view. |
void | addView(View child, ViewGroup.LayoutParams params) Adds a child view with the specified layout parameters. |
void | addView(View child, int index, ViewGroup.LayoutParams params) Adds a child view with the specified layout parameters. |
boolean | arrowScroll(int direction) Handle scrolling in response to a left or right arrow click. |
void | computeScroll() Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary. |
boolean | dispatchKeyEvent(KeyEvent event) Dispatch a key event to the next view on the focus path. |
void | draw(Canvas canvas) Manually render this view (and all of its children) to the given Canvas. |
boolean | executeKeyEvent(KeyEvent event) You can call this function yourself to have the scroll view perform scrolling from a key event, just as if the event had been dispatched to it by the view hierarchy. |
void | fling(int velocityX) Fling the scroll view |
boolean | fullScroll(int direction) Handles scrolling in response to a "home/end" shortcut press. |
CharSequence | getAccessibilityClassName() Return the class name of this object to be used for accessibility purposes. |
int | getLeftEdgeEffectColor() Returns the left edge effect color. |
int | getMaxScrollAmount() |
int | getRightEdgeEffectColor() Returns the right edge effect color. |
boolean | isFillViewport() Indicates whether this HorizontalScrollView's content is stretched to fill the viewport. |
boolean | isSmoothScrollingEnabled() |
boolean | onGenericMotionEvent(MotionEvent event) Implement this method to handle generic motion events. |
boolean | onInterceptTouchEvent(MotionEvent ev) Implement this method to intercept all touch screen motion events. |
boolean | onTouchEvent(MotionEvent ev) Implement this method to handle touch screen motion events. |
boolean | pageScroll(int direction) Handles scrolling in response to a "page up/down" shortcut press. |
void | requestChildFocus(View child, View focused) Called when a child of this parent wants focus |
boolean | requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) Called when a child of this group wants a particular rectangle to be positioned onto the screen. |
void | requestDisallowInterceptTouchEvent(boolean disallowIntercept) Called when a child does not want this parent and its ancestors to intercept touch events with |
void | requestLayout() Call this when something has changed which has invalidated the layout of this view. |
void | scrollTo(int x, int y) Set the scrolled position of your view. This version also clamps the scrolling to the bounds of our child. |
void | setEdgeEffectColor(int color) Sets the edge effect color for both left and right edge effects. |
void | setFillViewport(boolean fillViewport) Indicates this HorizontalScrollView whether it should stretch its content width to fill the viewport or not. |
void | setLeftEdgeEffectColor(int color) Sets the left edge effect color. |
void | setRightEdgeEffectColor(int color) Sets the right edge effect color. |
void | setSmoothScrollingEnabled(boolean smoothScrollingEnabled) Set whether arrow scrolling will animate its transition. |
boolean | shouldDelayChildPressedState() Return true if the pressed state should be delayed for children or descendants of this ViewGroup. |
final void | smoothScrollBy(int dx, int dy) Like |
final void | smoothScrollTo(int x, int y) Like |
Protected methods | |
---|---|
int | computeHorizontalScrollOffset() Compute the horizontal offset of the horizontal scrollbar's thumb within the horizontal range. |
int | computeHorizontalScrollRange() The scroll range of a scroll view is the overall width of all of its children. |
int | computeScrollDeltaToGetChildRectOnScreen(Rect rect) Compute the amount to scroll in the X direction in order to get a rectangle completely on the screen (or, if taller than the screen, at least the first screen size chunk of it). |
float | getLeftFadingEdgeStrength() Returns the strength, or intensity, of the left faded edge. |
float | getRightFadingEdgeStrength() Returns the strength, or intensity, of the right faded edge. |
void | measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) Ask one of the children of this view to measure itself, taking into account both the MeasureSpec requirements for this view and its padding. |
void | measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed) Ask one of the children of this view to measure itself, taking into account both the MeasureSpec requirements for this view and its padding and margins. |
void | onLayout(boolean changed, int l, int t, int r, int b) Called from layout when this view should assign a size and position to each of its children. |
void | onMeasure(int widthMeasureSpec, int heightMeasureSpec) Measure the view and its content to determine the measured width and the measured height. |
void | onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) Called by |
boolean | onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) When looking for focus in children of a scroll view, need to be a little more careful not to give focus to something that is scrolled off screen. |
void | onRestoreInstanceState(Parcelable state) Hook allowing a view to re-apply a representation of its internal state that had previously been generated by |
Parcelable | onSaveInstanceState() Hook allowing a view to generate a representation of its internal state that can later be used to create a new instance with that same state. |
void | onSizeChanged(int w, int h, int oldw, int oldh) This is called during layout when the size of this view has changed. |
Inherited methods | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
From class
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From class
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From class
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From class
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From interface
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From interface
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From interface
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From interface
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From interface
|
XML attributes
android:fillViewport
Defines whether the scrollview should stretch its content to fill the viewport.
May be a boolean value, such as "true
" or "false
".
Related methods:
-
setFillViewport(boolean)
Public constructors
HorizontalScrollView
public HorizontalScrollView (Context context)
Parameters | |
---|---|
context | Context |
HorizontalScrollView
public HorizontalScrollView (Context context, AttributeSet attrs)
Parameters | |
---|---|
context | Context |
attrs | AttributeSet |
HorizontalScrollView
public HorizontalScrollView (Context context, AttributeSet attrs, int defStyleAttr)
Parameters | |
---|---|
context | Context |
attrs | AttributeSet |
defStyleAttr | int |
HorizontalScrollView
public HorizontalScrollView (Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)
Parameters | |
---|---|
context | Context |
attrs | AttributeSet |
defStyleAttr | int |
defStyleRes | int |
Public methods
arrowScroll
public boolean arrowScroll (int direction)
Handle scrolling in response to a left or right arrow click.
Parameters | |
---|---|
direction | int : The direction corresponding to the arrow key that was pressed |
Returns | |
---|---|
boolean | True if we consumed the event, false otherwise |
computeScroll
public void computeScroll ()
Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary. This will typically be done if the child is animating a scroll using a Scroller
object.
dispatchKeyEvent
public boolean dispatchKeyEvent (KeyEvent event)
Dispatch a key event to the next view on the focus path. This path runs from the top of the view tree down to the currently focused view. If this view has focus, it will dispatch to itself. Otherwise it will dispatch the next node down the focus path. This method also fires any key listeners.
Parameters | |
---|---|
event | KeyEvent : The key event to be dispatched. |
Returns | |
---|---|
boolean | True if the event was handled, false otherwise. |
draw
public void draw (Canvas canvas)
Manually render this view (and all of its children) to the given Canvas. The view must have already done a full layout before this function is called. When implementing a view, implement onDraw(android.graphics.Canvas)
instead of overriding this method. If you do need to override this method, call the superclass version.
If you override this method you must call through to the superclass implementation.
Parameters | |
---|---|
canvas | Canvas : The Canvas to which the View is rendered. |
executeKeyEvent
public boolean executeKeyEvent (KeyEvent event)
You can call this function yourself to have the scroll view perform scrolling from a key event, just as if the event had been dispatched to it by the view hierarchy.
Parameters | |
---|---|
event | KeyEvent : The key event to execute. |
Returns | |
---|---|
boolean | Return true if the event was handled, else false. |
fling
public void fling (int velocityX)
Fling the scroll view
Parameters | |
---|---|
velocityX | int : The initial velocity in the X direction. Positive numbers mean that the finger/cursor is moving down the screen, which means we want to scroll towards the left. |
fullScroll
public boolean fullScroll (int direction)
Handles scrolling in response to a "home/end" shortcut press. This method will scroll the view to the left or right and give the focus to the leftmost/rightmost component in the new visible area. If no component is a good candidate for focus, this scrollview reclaims the focus.
Parameters | |
---|---|
direction | int : the scroll direction: View.FOCUS_LEFT to go the left of the view or View.FOCUS_RIGHT to go the right |
Returns | |
---|---|
boolean | true if the key event is consumed by this method, false otherwise |
getAccessibilityClassName
public CharSequence getAccessibilityClassName ()
Return the class name of this object to be used for accessibility purposes. Subclasses should only override this if they are implementing something that should be seen as a completely new class of view when used by accessibility, unrelated to the class it is deriving from. This is used to fill in AccessibilityNodeInfo.setClassName
.
Returns | |
---|---|
CharSequence |
getLeftEdgeEffectColor
public int getLeftEdgeEffectColor ()
Returns the left edge effect color.
Returns | |
---|---|
int | The left edge effect color. |
getMaxScrollAmount
public int getMaxScrollAmount ()
Returns | |
---|---|
int | The maximum amount this scroll view will scroll in response to an arrow event. |
getRightEdgeEffectColor
public int getRightEdgeEffectColor ()
Returns the right edge effect color.
Returns | |
---|---|
int | The right edge effect color. |
isFillViewport
public boolean isFillViewport ()
Indicates whether this HorizontalScrollView's content is stretched to fill the viewport.
Related XML Attributes:
- android:fillViewport
Returns | |
---|---|
boolean | True if the content fills the viewport, false otherwise. |
isSmoothScrollingEnabled
public boolean isSmoothScrollingEnabled ()
Returns | |
---|---|
boolean | Whether arrow scrolling will animate its transition. |
onGenericMotionEvent
public boolean onGenericMotionEvent (MotionEvent event)
Implement this method to handle generic motion events.
Generic motion events describe joystick movements, mouse hovers, track pad touches, scroll wheel movements and other input events. The source
of the motion event specifies the class of input that was received. Implementations of this method must examine the bits in the source before processing the event. The following code example shows how this is done.
Generic motion events with source class InputDevice#SOURCE_CLASS_POINTER
are delivered to the view under the pointer. All other generic motion events are delivered to the focused view.
public boolean onGenericMotionEvent(MotionEvent event) { if (event.isFromSource(InputDevice.SOURCE_CLASS_JOYSTICK)) { if (event.getAction() == MotionEvent.ACTION_MOVE) { // process the joystick movement... return true; } } if (event.isFromSource(InputDevice.SOURCE_CLASS_POINTER)) { switch (event.getAction()) { case MotionEvent.ACTION_HOVER_MOVE: // process the mouse hover movement... return true; case MotionEvent.ACTION_SCROLL: // process the scroll wheel movement... return true; } } return super.onGenericMotionEvent(event); }
Parameters | |
---|---|
event | MotionEvent : The generic motion event being processed. |
Returns | |
---|---|
boolean | True if the event was handled, false otherwise. |
onInterceptTouchEvent
public boolean onInterceptTouchEvent (MotionEvent ev)
Implement this method to intercept all touch screen motion events. This allows you to watch events as they are dispatched to your children, and take ownership of the current gesture at any point.
Using this function takes some care, as it has a fairly complicated interaction with View.onTouchEvent(MotionEvent)
, and using it requires implementing that method as well as this one in the correct way. Events will be received in the following order:
- You will receive the down event here.
- The down event will be handled either by a child of this view group, or given to your own onTouchEvent() method to handle; this means you should implement onTouchEvent() to return true, so you will continue to see the rest of the gesture (instead of looking for a parent view to handle it). Also, by returning true from onTouchEvent(), you will not receive any following events in onInterceptTouchEvent() and all touch processing must happen in onTouchEvent() like normal.
- For as long as you return false from this function, each following event (up to and including the final up) will be delivered first here and then to the target's onTouchEvent().
- If you return true from here, you will not receive any following events: the target view will receive the same event but with the action
MotionEvent#ACTION_CANCEL
, and all further events will be delivered to your onTouchEvent() method and no longer appear here.
Parameters | |
---|---|
ev | MotionEvent : The motion event being dispatched down the hierarchy. |
Returns | |
---|---|
boolean | Return true to steal motion events from the children and have them dispatched to this ViewGroup through onTouchEvent(). The current target will receive an ACTION_CANCEL event, and no further messages will be delivered here. |
onTouchEvent
public boolean onTouchEvent (MotionEvent ev)
Implement this method to handle touch screen motion events.
If this method is used to detect click actions, it is recommended that the actions be performed by implementing and calling performClick()
. This will ensure consistent system behavior, including:
- obeying click sound preferences
- dispatching OnClickListener calls
- handling
ACTION_CLICK
when accessibility features are enabled
Parameters | |
---|---|
ev | MotionEvent : The motion event. |
Returns | |
---|---|
boolean | True if the event was handled, false otherwise. |
pageScroll
public boolean pageScroll (int direction)
Handles scrolling in response to a "page up/down" shortcut press. This method will scroll the view by one page left or right and give the focus to the leftmost/rightmost component in the new visible area. If no component is a good candidate for focus, this scrollview reclaims the focus.
Parameters | |
---|---|
direction | int : the scroll direction: View.FOCUS_LEFT to go one page left or View.FOCUS_RIGHT to go one page right |
Returns | |
---|---|
boolean | true if the key event is consumed by this method, false otherwise |
requestChildFocus
public void requestChildFocus (View child, View focused)
Called when a child of this parent wants focus
Parameters | |
---|---|
child | View : The child of this ViewParent that wants focus. This view will contain the focused view. It is not necessarily the view that actually has focus. |
focused | View : The view that is a descendant of child that actually has focus |
requestChildRectangleOnScreen
public boolean requestChildRectangleOnScreen (View child, Rect rectangle, boolean immediate)
Called when a child of this group wants a particular rectangle to be positioned onto the screen. ViewGroup
s overriding this can trust that:
- child will be a direct child of this group
- rectangle will be in the child's content coordinates
ViewGroup
s overriding this should uphold the contract:
- nothing will change if the rectangle is already visible
- the view port will be scrolled only just enough to make the rectangle visible
Parameters | |
---|---|
child | View : The direct child making the request. |
rectangle | Rect : The rectangle in the child's coordinates the child wishes to be on the screen. |
immediate | boolean : True to forbid animated or delayed scrolling, false otherwise |
Returns | |
---|---|
boolean | Whether the group scrolled to handle the operation |
requestDisallowInterceptTouchEvent
public void requestDisallowInterceptTouchEvent (boolean disallowIntercept)
Called when a child does not want this parent and its ancestors to intercept touch events with ViewGroup#onInterceptTouchEvent(MotionEvent)
.
This parent should pass this call onto its parents. This parent must obey this request for the duration of the touch (that is, only clear the flag after this parent has received an up or a cancel.
Parameters | |
---|---|
disallowIntercept | boolean : True if the child does not want the parent to intercept touch events. |
requestLayout
public void requestLayout ()
Call this when something has changed which has invalidated the layout of this view. This will schedule a layout pass of the view tree. This should not be called while the view hierarchy is currently in a layout pass (isInLayout()
. If layout is happening, the request may be honored at the end of the current layout pass (and then layout will run again) or after the current frame is drawn and the next layout occurs.
Subclasses which override this method should call the superclass method to handle possible request-during-layout errors correctly.
If you override this method you must call through to the superclass implementation.
scrollTo
public void scrollTo (int x, int y)
Set the scrolled position of your view. This will cause a call to onScrollChanged(int, int, int, int)
and the view will be invalidated.
This version also clamps the scrolling to the bounds of our child.
Parameters | |
---|---|
x | int : the x position to scroll to |
y | int : the y position to scroll to |
setEdgeEffectColor
public void setEdgeEffectColor (int color)
Sets the edge effect color for both left and right edge effects.
Parameters | |
---|---|
color | int : The color for the edge effects. |
setFillViewport
public void setFillViewport (boolean fillViewport)
Indicates this HorizontalScrollView whether it should stretch its content width to fill the viewport or not.
Related XML Attributes:
- android:fillViewport
Parameters | |
---|---|
fillViewport | boolean : True to stretch the content's width to the viewport's boundaries, false otherwise. |
setLeftEdgeEffectColor
public void setLeftEdgeEffectColor (int color)
Sets the left edge effect color.
Parameters | |
---|---|
color | int : The color for the left edge effect. |
setRightEdgeEffectColor
public void setRightEdgeEffectColor (int color)
Sets the right edge effect color.
Parameters | |
---|---|
color | int : The color for the right edge effect. |
setSmoothScrollingEnabled
public void setSmoothScrollingEnabled (boolean smoothScrollingEnabled)
Set whether arrow scrolling will animate its transition.
Parameters | |
---|---|
smoothScrollingEnabled | boolean : whether arrow scrolling will animate its transition |
shouldDelayChildPressedState
public boolean shouldDelayChildPressedState ()
Return true if the pressed state should be delayed for children or descendants of this ViewGroup. Generally, this should be done for containers that can scroll, such as a List. This prevents the pressed state from appearing when the user is actually trying to scroll the content. The default implementation returns true for compatibility reasons. Subclasses that do not scroll should generally override this method and return false.
Returns | |
---|---|
boolean |
smoothScrollBy
public final void smoothScrollBy (int dx, int dy)
Like View#scrollBy
, but scroll smoothly instead of immediately.
Parameters | |
---|---|
dx | int : the number of pixels to scroll by on the X axis |
dy | int : the number of pixels to scroll by on the Y axis |
smoothScrollTo
public final void smoothScrollTo (int x, int y)
Like scrollTo(int, int)
, but scroll smoothly instead of immediately.
Parameters | |
---|---|
x | int : the position where to scroll on the X axis |
y | int : the position where to scroll on the Y axis |
Protected methods
computeHorizontalScrollOffset
protected int computeHorizontalScrollOffset ()
Compute the horizontal offset of the horizontal scrollbar's thumb within the horizontal range. This value is used to compute the position of the thumb within the scrollbar's track.
The range is expressed in arbitrary units that must be the same as the units used by computeHorizontalScrollRange()
and computeHorizontalScrollExtent()
.
The default offset is the scroll offset of this view.
Returns | |
---|---|
int | the horizontal offset of the scrollbar's thumb |
computeHorizontalScrollRange
protected int computeHorizontalScrollRange ()
The scroll range of a scroll view is the overall width of all of its children.
Returns | |
---|---|
int | the total horizontal range represented by the horizontal scrollbar |
computeScrollDeltaToGetChildRectOnScreen
protected int computeScrollDeltaToGetChildRectOnScreen (Rect rect)
Compute the amount to scroll in the X direction in order to get a rectangle completely on the screen (or, if taller than the screen, at least the first screen size chunk of it).
Parameters | |
---|---|
rect | Rect : The rect. |
Returns | |
---|---|
int | The scroll delta. |
getLeftFadingEdgeStrength
protected float getLeftFadingEdgeStrength ()
Returns the strength, or intensity, of the left faded edge. The strength is a value between 0.0 (no fade) and 1.0 (full fade). The default implementation returns 0.0 or 1.0 but no value in between. Subclasses should override this method to provide a smoother fade transition when scrolling occurs.
Returns | |
---|---|
float | the intensity of the left fade as a float between 0.0f and 1.0f |
getRightFadingEdgeStrength
protected float getRightFadingEdgeStrength ()
Returns the strength, or intensity, of the right faded edge. The strength is a value between 0.0 (no fade) and 1.0 (full fade). The default implementation returns 0.0 or 1.0 but no value in between. Subclasses should override this method to provide a smoother fade transition when scrolling occurs.
Returns | |
---|---|
float | the intensity of the right fade as a float between 0.0f and 1.0f |
measureChild
protected void measureChild (View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec)
Ask one of the children of this view to measure itself, taking into account both the MeasureSpec requirements for this view and its padding. The heavy lifting is done in getChildMeasureSpec.
Parameters | |
---|---|
child | View : The child to measure |
parentWidthMeasureSpec | int : The width requirements for this view |
parentHeightMeasureSpec | int : The height requirements for this view |
measureChildWithMargins
protected void measureChildWithMargins (View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed)
Ask one of the children of this view to measure itself, taking into account both the MeasureSpec requirements for this view and its padding and margins. The child must have MarginLayoutParams The heavy lifting is done in getChildMeasureSpec.
Parameters | |
---|---|
child | View : The child to measure |
parentWidthMeasureSpec | int : The width requirements for this view |
widthUsed | int : Extra space that has been used up by the parent horizontally (possibly by other children of the parent) |
parentHeightMeasureSpec | int : The height requirements for this view |
heightUsed | int : Extra space that has been used up by the parent vertically (possibly by other children of the parent) |
onLayout
protected void onLayout (boolean changed, int l, int t, int r, int b)
Called from layout when this view should assign a size and position to each of its children. Derived classes with children should override this method and call layout on each of their children.
Parameters | |
---|---|
changed | boolean : This is a new size or position for this view |
l | int : Left position, relative to parent |
t | int : Top position, relative to parent |
r | int : Right position, relative to parent |
b | int : Bottom position, relative to parent |
onMeasure
protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec)
Measure the view and its content to determine the measured width and the measured height. This method is invoked by measure(int, int)
and should be overridden by subclasses to provide accurate and efficient measurement of their contents.
CONTRACT: When overriding this method, you must call setMeasuredDimension(int, int)
to store the measured width and height of this view. Failure to do so will trigger an IllegalStateException
, thrown by measure(int, int)
. Calling the superclass' onMeasure(int, int)
is a valid use.
The base class implementation of measure defaults to the background size, unless a larger size is allowed by the MeasureSpec. Subclasses should override onMeasure(int, int)
to provide better measurements of their content.
If this method is overridden, it is the subclass's responsibility to make sure the measured height and width are at least the view's minimum height and width (getSuggestedMinimumHeight()
and getSuggestedMinimumWidth()
).
Parameters | |
---|---|
widthMeasureSpec | int : horizontal space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec . |
heightMeasureSpec | int : vertical space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec . |
onOverScrolled
protected void onOverScrolled (int scrollX, int scrollY, boolean clampedX, boolean clampedY)
Called by overScrollBy(int, int, int, int, int, int, int, int, boolean)
to respond to the results of an over-scroll operation.
Parameters | |
---|---|
scrollX | int : New X scroll value in pixels |
scrollY | int : New Y scroll value in pixels |
clampedX | boolean : True if scrollX was clamped to an over-scroll boundary |
clampedY | boolean : True if scrollY was clamped to an over-scroll boundary |
onRequestFocusInDescendants
protected boolean onRequestFocusInDescendants (int direction, Rect previouslyFocusedRect)
When looking for focus in children of a scroll view, need to be a little more careful not to give focus to something that is scrolled off screen. This is more expensive than the default ViewGroup
implementation, otherwise this behavior might have been made the default.
Parameters | |
---|---|
direction | int : One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT |
previouslyFocusedRect | Rect : The rectangle (in this View's coordinate system) to give a finer grained hint about where focus is coming from. May be null if there is no hint. |
Returns | |
---|---|
boolean | Whether focus was taken. |
onRestoreInstanceState
protected void onRestoreInstanceState (Parcelable state)
Hook allowing a view to re-apply a representation of its internal state that had previously been generated by onSaveInstanceState()
. This function will never be called with a null state.
If you override this method you must call through to the superclass implementation.
Parameters | |
---|---|
state | Parcelable : The frozen state that had previously been returned by onSaveInstanceState() . |
onSaveInstanceState
protected Parcelable onSaveInstanceState ()
Hook allowing a view to generate a representation of its internal state that can later be used to create a new instance with that same state. This state should only contain information that is not persistent or can not be reconstructed later. For example, you will never store your current position on screen because that will be computed again when a new instance of the view is placed in its view hierarchy.
Some examples of things you may store here: the current cursor position in a text view (but usually not the text itself since that is stored in a content provider or other persistent storage), the currently selected item in a list view.
If you override this method you must call through to the superclass implementation.
Returns | |
---|---|
Parcelable | Returns a Parcelable object containing the view's current dynamic state, or null if there is nothing interesting to save. |
onSizeChanged
protected void onSizeChanged (int w, int h, int oldw, int oldh)
This is called during layout when the size of this view has changed. If you were just added to the view hierarchy, you're called with the old values of 0.
Parameters | |
---|---|
w | int : Current width of this view. |
h | int : Current height of this view. |
oldw | int : Old width of this view. |
oldh | int : Old height of this view. |
Content and code samples on this page are subject to the licenses described in the Content License. Java is a registered trademark of Oracle and/or its affiliates.
Last updated 2021-12-08 UTC.
Horizontal Scroll View Line Drawing
Source: https://developer.android.com/reference/android/widget/HorizontalScrollView
0 Response to "Horizontal Scroll View Line Drawing"
Post a Comment