Inheritance diagram for com.freerdp.freerdpcore.presentation.ScrollView2D:

Collaboration diagram for com.freerdp.freerdpcore.presentation.ScrollView2D:

Data Structures
interface	ScrollView2DListener

Public Member Functions
	ScrollView2D (Context context)

	ScrollView2D (Context context, AttributeSet attrs)

	ScrollView2D (Context context, AttributeSet attrs, int defStyle)

void	setScrollEnabled (boolean enable)

int	getMaxScrollAmountVertical ()

int	getMaxScrollAmountHorizontal ()

void	addView (View child)

void	addView (View child, int index)

void	addView (View child, ViewGroup.LayoutParams params)

void	addView (View child, int index, ViewGroup.LayoutParams params)

boolean	dispatchKeyEvent (KeyEvent event)

boolean	executeKeyEvent (KeyEvent event)

boolean	onInterceptTouchEvent (MotionEvent ev)

boolean	onTouchEvent (MotionEvent ev)

boolean	fullScroll (int direction, boolean horizontal)

boolean	arrowScroll (int direction, boolean horizontal)

final void	smoothScrollBy (int dx, int dy)

final void	smoothScrollTo (int x, int y)

void	computeScroll ()

void	requestChildFocus (View child, View focused)

boolean	requestChildRectangleOnScreen (View child, Rect rectangle, boolean immediate)

void	requestLayout ()

void	fling (int velocityX, int velocityY)

void	scrollTo (int x, int y)

void	setScrollViewListener (ScrollView2DListener scrollViewListener)

Protected Member Functions
float	getTopFadingEdgeStrength ()

float	getBottomFadingEdgeStrength ()

float	getLeftFadingEdgeStrength ()

float	getRightFadingEdgeStrength ()

int	computeVerticalScrollRange ()

int	computeHorizontalScrollRange ()

void	measureChild (View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec)

void	measureChildWithMargins (View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed)

int	computeScrollDeltaToGetChildRectOnScreen (Rect rect)

boolean	onRequestFocusInDescendants (int direction, Rect previouslyFocusedRect)

void	onLayout (boolean changed, int l, int t, int r, int b)

void	onSizeChanged (int w, int h, int oldw, int oldh)

void	onScrollChanged (int x, int y, int oldx, int oldy)

Detailed Description

Layout container for a view hierarchy that can be scrolled by the user, allowing it to be larger than the physical display. A TwoDScrollView 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 vertical orientation, presenting a vertical 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 TwoDScrollView, but using the two together is possible to achieve the effect of a text view within a larger container.

Definition at line 57 of file ScrollView2D.java.

Member Function Documentation

◆ arrowScroll()

boolean com.freerdp.freerdpcore.presentation.ScrollView2D.arrowScroll	(	int	direction,
		boolean	horizontal
	)

inline

Handle scrolling in response to an up or down arrow click.

Parameters

direction The direction corresponding to the arrow key that was pressed

Returns: True if we consumed the event, false otherwise

Definition at line 785 of file ScrollView2D.java.

   {
     View currentFocused = findFocus();
     if (currentFocused == this)
       currentFocused = null;
     View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
     final int maxJump =
         horizontal ? getMaxScrollAmountHorizontal() : getMaxScrollAmountVertical();
  
     if (!horizontal)
     {
       if (nextFocused != null)
       {
         nextFocused.getDrawingRect(mTempRect);
         offsetDescendantRectToMyCoords(nextFocused, mTempRect);
         int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
         doScroll(0, scrollDelta);
         nextFocused.requestFocus(direction);
       }
       else
       {
         // no new focus
         int scrollDelta = maxJump;
         if (direction == View.FOCUS_UP && getScrollY() < scrollDelta)
         {
           scrollDelta = getScrollY();
         }
         else if (direction == View.FOCUS_DOWN)
         {
           if (getChildCount() > 0)
           {
             int daBottom = getChildAt(0).getBottom();
             int screenBottom = getScrollY() + getHeight();
             if (daBottom - screenBottom < maxJump)
             {
               scrollDelta = daBottom - screenBottom;
             }
           }
         }
         if (scrollDelta == 0)
         {
           return false;
         }
         doScroll(0, direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta);
       }
     }
     else
     {
       if (nextFocused != null)
       {
         nextFocused.getDrawingRect(mTempRect);
         offsetDescendantRectToMyCoords(nextFocused, mTempRect);
         int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
         doScroll(scrollDelta, 0);
         nextFocused.requestFocus(direction);
       }
       else
       {
         // no new focus
         int scrollDelta = maxJump;
         if (direction == View.FOCUS_UP && getScrollY() < scrollDelta)
         {
           scrollDelta = getScrollY();
         }
         else if (direction == View.FOCUS_DOWN)
         {
           if (getChildCount() > 0)
           {
             int daBottom = getChildAt(0).getBottom();
             int screenBottom = getScrollY() + getHeight();
             if (daBottom - screenBottom < maxJump)
             {
               scrollDelta = daBottom - screenBottom;
             }
           }
         }
         if (scrollDelta == 0)
         {
           return false;
         }
         doScroll(direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta, 0);
       }
     }
     return true;
   }

References com.freerdp.freerdpcore.presentation.ScrollView2D.computeScrollDeltaToGetChildRectOnScreen(), and com.freerdp.freerdpcore.presentation.ScrollView2D.getMaxScrollAmountVertical().

Referenced by com.freerdp.freerdpcore.presentation.ScrollView2D.executeKeyEvent().

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◆ computeScrollDeltaToGetChildRectOnScreen()

int com.freerdp.freerdpcore.presentation.ScrollView2D.computeScrollDeltaToGetChildRectOnScreen ( Rect rect )

inlineprotected

Compute the amount to scroll in the Y 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 The rect.

Returns: The scroll delta.

Definition at line 1061 of file ScrollView2D.java.

   {
     if (getChildCount() == 0)
       return 0;
     int height = getHeight();
     int screenTop = getScrollY();
     int screenBottom = screenTop + height;
     int fadingEdge = getVerticalFadingEdgeLength();
     // leave room for top fading edge as long as rect isn't at very top
     if (rect.top > 0)
     {
       screenTop += fadingEdge;
     }
  
     // leave room for bottom fading edge as long as rect isn't at very bottom
     if (rect.bottom < getChildAt(0).getHeight())
     {
       screenBottom -= fadingEdge;
     }
     int scrollYDelta = 0;
     if (rect.bottom > screenBottom && rect.top > screenTop)
     {
       // need to move down to get it in view: move down just enough so
       // that the entire rectangle is in view (or at least the first
       // screen size chunk).
       if (rect.height() > height)
       {
         // just enough to get screen size chunk on
         scrollYDelta += (rect.top - screenTop);
       }
       else
       {
         // get entire rect at bottom of screen
         scrollYDelta += (rect.bottom - screenBottom);
       }
  
       // make sure we aren't scrolling beyond the end of our content
       int bottom = getChildAt(0).getBottom();
       int distanceToBottom = bottom - screenBottom;
       scrollYDelta = Math.min(scrollYDelta, distanceToBottom);
     }
     else if (rect.top < screenTop && rect.bottom < screenBottom)
     {
       // need to move up to get it in view: move up just enough so that
       // entire rectangle is in view (or at least the first screen
       // size chunk of it).
  
       if (rect.height() > height)
       {
         // screen size chunk
         scrollYDelta -= (screenBottom - rect.bottom);
       }
       else
       {
         // entire rect at top
         scrollYDelta -= (screenTop - rect.top);
       }
  
       // make sure we aren't scrolling any further than the top our content
       scrollYDelta = Math.max(scrollYDelta, -getScrollY());
     }
     return scrollYDelta;
   }

Referenced by com.freerdp.freerdpcore.presentation.ScrollView2D.arrowScroll().

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◆ computeVerticalScrollRange()

int com.freerdp.freerdpcore.presentation.ScrollView2D.computeVerticalScrollRange ( )

inlineprotected

The scroll range of a scroll view is the overall height of all of its children.

Definition at line 925 of file ScrollView2D.java.

   {
     int count = getChildCount();
     return count == 0 ? getHeight() : (getChildAt(0)).getBottom();
   }

◆ executeKeyEvent()

boolean com.freerdp.freerdpcore.presentation.ScrollView2D.executeKeyEvent ( KeyEvent event )

inline

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 The key event to execute.

Returns: Return true if the event was handled, else false.

Definition at line 290 of file ScrollView2D.java.

   {
     mTempRect.setEmpty();
     if (!canScroll())
     {
       if (isFocused())
       {
         View currentFocused = findFocus();
         if (currentFocused == this)
           currentFocused = null;
         View nextFocused =
             FocusFinder.getInstance().findNextFocus(this, currentFocused, View.FOCUS_DOWN);
         return nextFocused != null && nextFocused != this &&
             nextFocused.requestFocus(View.FOCUS_DOWN);
       }
       return false;
     }
     boolean handled = false;
     if (event.getAction() == KeyEvent.ACTION_DOWN)
     {
       switch (event.getKeyCode())
       {
         case KeyEvent.KEYCODE_DPAD_UP:
           if (!event.isAltPressed())
           {
             handled = arrowScroll(View.FOCUS_UP, false);
           }
           else
           {
             handled = fullScroll(View.FOCUS_UP, false);
           }
           break;
         case KeyEvent.KEYCODE_DPAD_DOWN:
           if (!event.isAltPressed())
           {
             handled = arrowScroll(View.FOCUS_DOWN, false);
           }
           else
           {
             handled = fullScroll(View.FOCUS_DOWN, false);
           }
           break;
         case KeyEvent.KEYCODE_DPAD_LEFT:
           if (!event.isAltPressed())
           {
             handled = arrowScroll(View.FOCUS_LEFT, true);
           }
           else
           {
             handled = fullScroll(View.FOCUS_LEFT, true);
           }
           break;
         case KeyEvent.KEYCODE_DPAD_RIGHT:
           if (!event.isAltPressed())
           {
             handled = arrowScroll(View.FOCUS_RIGHT, true);
           }
           else
           {
             handled = fullScroll(View.FOCUS_RIGHT, true);
           }
           break;
       }
     }
     return handled;
   }

References com.freerdp.freerdpcore.presentation.ScrollView2D.arrowScroll(), and com.freerdp.freerdpcore.presentation.ScrollView2D.fullScroll().

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◆ fling()

void com.freerdp.freerdpcore.presentation.ScrollView2D.fling	(	int	velocityX,
		int	velocityY
	)

inline

Fling the scroll view

Parameters

velocityY The initial velocity in the Y direction. Positive numbers mean that the finger/curor is moving down the screen, which means we want to scroll towards the top.

Definition at line 1244 of file ScrollView2D.java.

   {
     if (getChildCount() > 0)
     {
       int height = getHeight() - getPaddingBottom() - getPaddingTop();
       int bottom = getChildAt(0).getHeight();
       int width = getWidth() - getPaddingRight() - getPaddingLeft();
       int right = getChildAt(0).getWidth();
  
       mScroller.fling(getScrollX(), getScrollY(), velocityX, velocityY, 0, right - width, 0,
                       bottom - height);
  
       final boolean movingDown = velocityY > 0;
       final boolean movingRight = velocityX > 0;
  
       View newFocused = findFocusableViewInMyBounds(
           movingRight, mScroller.getFinalX(), movingDown, mScroller.getFinalY(), findFocus());
       if (newFocused == null)
       {
         newFocused = this;
       }
  
       if (newFocused != findFocus() &&
           newFocused.requestFocus(movingDown ? View.FOCUS_DOWN : View.FOCUS_UP))
       {
         mTwoDScrollViewMovedFocus = true;
         mTwoDScrollViewMovedFocus = false;
       }
  
       awakenScrollBars(mScroller.getDuration());
       invalidate();
     }
   }

◆ fullScroll()

boolean com.freerdp.freerdpcore.presentation.ScrollView2D.fullScroll	(	int	direction,
		boolean	horizontal
	)

inline

Handles scrolling in response to a "home/end" shortcut press. This method will scroll the view to the top or bottom and give the focus to the topmost/bottommost component in the new visible area. If no component is a good candidate for focus, this scrollview reclaims the focus.

Parameters

direction the scroll direction: android.view.View#FOCUS_UP to go the top of the view or android.view.View#FOCUS_DOWN to go the bottom

Returns: true if the key event is consumed by this method, false otherwise

Definition at line 689 of file ScrollView2D.java.

   {
     if (!horizontal)
     {
       boolean down = direction == View.FOCUS_DOWN;
       int height = getHeight();
       mTempRect.top = 0;
       mTempRect.bottom = height;
       if (down)
       {
         int count = getChildCount();
         if (count > 0)
         {
           View view = getChildAt(count - 1);
           mTempRect.bottom = view.getBottom();
           mTempRect.top = mTempRect.bottom - height;
         }
       }
       return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom, 0, 0, 0);
     }
     else
     {
       boolean right = direction == View.FOCUS_DOWN;
       int width = getWidth();
       mTempRect.left = 0;
       mTempRect.right = width;
       if (right)
       {
         int count = getChildCount();
         if (count > 0)
         {
           View view = getChildAt(count - 1);
           mTempRect.right = view.getBottom();
           mTempRect.left = mTempRect.right - width;
         }
       }
       return scrollAndFocus(0, 0, 0, direction, mTempRect.top, mTempRect.bottom);
     }
   }

Referenced by com.freerdp.freerdpcore.presentation.ScrollView2D.executeKeyEvent().

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◆ getMaxScrollAmountVertical()

int com.freerdp.freerdpcore.presentation.ScrollView2D.getMaxScrollAmountVertical ( )

inline

Returns: The maximum amount this scroll view will scroll in response to an arrow event.

Definition at line 195 of file ScrollView2D.java.

   {
     return (int)(MAX_SCROLL_FACTOR * getHeight());
   }

Referenced by com.freerdp.freerdpcore.presentation.ScrollView2D.arrowScroll().

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◆ onRequestFocusInDescendants()

boolean com.freerdp.freerdpcore.presentation.ScrollView2D.onRequestFocusInDescendants	(	int	direction,
		Rect	previouslyFocusedRect
	)

inlineprotected

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 android.view.ViewGroup implementation, otherwise this behavior might have been made the default.

Definition at line 1150 of file ScrollView2D.java.

   {
     // convert from forward / backward notation to up / down / left / right
     // (ugh).
     if (direction == View.FOCUS_FORWARD)
     {
       direction = View.FOCUS_DOWN;
     }
     else if (direction == View.FOCUS_BACKWARD)
     {
       direction = View.FOCUS_UP;
     }
  
     final View nextFocus = previouslyFocusedRect == null
                                ? FocusFinder.getInstance().findNextFocus(this, null, direction)
                                : FocusFinder.getInstance().findNextFocusFromRect(
                                      this, previouslyFocusedRect, direction);
  
     if (nextFocus == null)
     {
       return false;
     }
  
     return nextFocus.requestFocus(direction, previouslyFocusedRect);
   }

◆ scrollTo()

void com.freerdp.freerdpcore.presentation.ScrollView2D.scrollTo	(	int	x,
		int	y
	)

inline

This version also clamps the scrolling to the bounds of our child.

Definition at line 1283 of file ScrollView2D.java.

   {
     // we rely on the fact the View.scrollBy calls scrollTo.
     if (getChildCount() > 0)
     {
       View child = getChildAt(0);
       x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth());
       y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight());
       if (x != getScrollX() || y != getScrollY())
       {
         super.scrollTo(x, y);
       }
     }
   }

◆ setScrollEnabled()

void com.freerdp.freerdpcore.presentation.ScrollView2D.setScrollEnabled ( boolean enable )

inline

Disable/Enable scrolling

Definition at line 186 of file ScrollView2D.java.

   {
     scrollEnabled = enable;
   }

◆ smoothScrollBy()

final void com.freerdp.freerdpcore.presentation.ScrollView2D.smoothScrollBy	(	int	dx,
		int	dy
	)

inline

Like View#scrollBy, but scroll smoothly instead of immediately.

Parameters

dx	the number of pixels to scroll by on the X axis
dy	the number of pixels to scroll by on the Y axis

Definition at line 890 of file ScrollView2D.java.

   {
     long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll;
     if (duration > ANIMATED_SCROLL_GAP)
     {
       mScroller.startScroll(getScrollX(), getScrollY(), dx, dy);
       awakenScrollBars(mScroller.getDuration());
       invalidate();
     }
     else
     {
       if (!mScroller.isFinished())
       {
         mScroller.abortAnimation();
       }
       scrollBy(dx, dy);
     }
     mLastScroll = AnimationUtils.currentAnimationTimeMillis();
   }

Referenced by com.freerdp.freerdpcore.presentation.ScrollView2D.smoothScrollTo().

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◆ smoothScrollTo()

final void com.freerdp.freerdpcore.presentation.ScrollView2D.smoothScrollTo	(	int	x,
		int	y
	)

inline

Like scrollTo, but scroll smoothly instead of immediately.

Parameters

x	the position where to scroll on the X axis
y	the position where to scroll on the Y axis

Definition at line 916 of file ScrollView2D.java.

   {
     smoothScrollBy(x - getScrollX(), y - getScrollY());
   }

References com.freerdp.freerdpcore.presentation.ScrollView2D.smoothScrollBy().

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The documentation for this class was generated from the following file:

ScrollView2D.java

Data Structures

Public Member Functions

Protected Member Functions

Detailed Description

Member Function Documentation

◆ arrowScroll()

◆ computeScrollDeltaToGetChildRectOnScreen()

◆ computeVerticalScrollRange()

◆ executeKeyEvent()

◆ fling()

◆ fullScroll()

◆ getMaxScrollAmountVertical()

◆ onRequestFocusInDescendants()

◆ scrollTo()

◆ setScrollEnabled()

◆ smoothScrollBy()

◆ smoothScrollTo()