Java Code Examples for android.view.View#findFocus()

private boolean handleHorizontalFocusWithinListItem(int direction) {
    if (direction == 33 || direction == 130) {
        int numChildren = getChildCount();
        if (this.mItemsCanFocus && numChildren > 0 && this.mSelectedPosition != -1) {
            View selectedView = getSelectedView();
            if (selectedView != null && selectedView.hasFocus() && (selectedView instanceof ViewGroup)) {
                View currentFocus = selectedView.findFocus();
                View nextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) selectedView, currentFocus, direction);
                if (nextFocus != null) {
                    currentFocus.getFocusedRect(this.mTempRect);
                    offsetDescendantRectToMyCoords(currentFocus, this.mTempRect);
                    offsetRectIntoDescendantCoords(nextFocus, this.mTempRect);
                    if (nextFocus.requestFocus(direction, this.mTempRect)) {
                        return true;
                    }
                }
                View globalNextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) getRootView(), currentFocus, direction);
                if (globalNextFocus != null) {
                    return isViewAncestorOf(globalNextFocus, this);
                }
            }
        }
        return false;
    }
    throw new IllegalArgumentException("direction must be one of {View.FOCUS_UP, View.FOCUS_DOWN}");
}
 

/**
 * 获取 View 里获取焦点的 View
 * @param view {@link View}
 * @return {@link View}
 */
public static View findFocus(final View view) {
    if (view != null) {
        return view.findFocus();
    }
    return null;
}
 

/**
 * To avoid horizontal focus searches changing the selected item, we manually focus search within the selected item (as
 * applicable), and prevent focus from jumping to something within another item.
 * 
 * @param direction
 *           one of {View.FOCUS_LEFT, View.FOCUS_RIGHT}
 * @return Whether this consumes the key event.
 */
private boolean handleHorizontalFocusWithinListItem( int direction ) {
	// TODO: implement this
	if ( direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT ) {
		throw new IllegalArgumentException( "direction must be one of"
				+ " {View.FOCUS_LEFT, View.FOCUS_RIGHT}" );
	}

	final int numChildren = getChildCount();
	if ( mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION ) {
		final View selectedView = getSelectedView();
		if ( selectedView != null && selectedView.hasFocus() &&
				selectedView instanceof ViewGroup ) {

			final View currentFocus = selectedView.findFocus();
			final View nextFocus = FocusFinder.getInstance().findNextFocus(
					(ViewGroup) selectedView, currentFocus, direction );
			if ( nextFocus != null ) {
				// do the math to get interesting rect in next focus' coordinates
				currentFocus.getFocusedRect( mTempRect );
				offsetDescendantRectToMyCoords( currentFocus, mTempRect );
				offsetRectIntoDescendantCoords( nextFocus, mTempRect );
				if ( nextFocus.requestFocus( direction, mTempRect ) ) {
					return true;
				}
			}
			// we are blocking the key from being handled (by returning true)
			// if the global result is going to be some other view within this
			// list. this is to acheive the overall goal of having
			// horizontal d-pad navigation remain in the current item.
			final View globalNextFocus = FocusFinder.getInstance().findNextFocus(
					(ViewGroup) getRootView(), currentFocus, direction );
			if ( globalNextFocus != null ) {
				return isViewAncestorOf( globalNextFocus, this );
			}
		}
	}
	return false;
}
 

/**
 * To avoid horizontal focus searches changing the selected item, we
 * manually focus search within the selected item (as applicable), and
 * prevent focus from jumping to something within another item.
 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT}
 * @return Whether this consumes the key event.
 */
private boolean handleHorizontalFocusWithinListItem(int direction) {
    if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT)  {
        throw new IllegalArgumentException("direction must be one of"
                + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}");
    }

    final int numChildren = getChildCount();
    if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) {
        final View selectedView = getSelectedView();
        if (selectedView != null && selectedView.hasFocus() &&
                selectedView instanceof ViewGroup) {

            final View currentFocus = selectedView.findFocus();
            final View nextFocus = FocusFinder.getInstance().findNextFocus(
                    (ViewGroup) selectedView, currentFocus, direction);
            if (nextFocus != null) {
                // do the math to get interesting rect in next focus' coordinates
                Rect focusedRect = mTempRect;
                if (currentFocus != null) {
                    currentFocus.getFocusedRect(focusedRect);
                    offsetDescendantRectToMyCoords(currentFocus, focusedRect);
                    offsetRectIntoDescendantCoords(nextFocus, focusedRect);
                } else {
                    focusedRect = null;
                }
                if (nextFocus.requestFocus(direction, focusedRect)) {
                    return true;
                }
            }
            // we are blocking the key from being handled (by returning true)
            // if the global result is going to be some other view within this
            // list.  this is to acheive the overall goal of having
            // horizontal d-pad navigation remain in the current item.
            final View globalNextFocus = FocusFinder.getInstance().findNextFocus(
                    (ViewGroup) getRootView(), currentFocus, direction);
            if (globalNextFocus != null) {
                return isViewAncestorOf(globalNextFocus, this);
            }
        }
    }
    return false;
}
 

private boolean arrowScrollImpl(int direction) {
    if (getChildCount() <= 0) {
        return false;
    }
    boolean needToRedraw;
    View focused;
    View selectedView = getSelectedView();
    int selectedPos = this.mSelectedPosition;
    int nextSelectedPosition = lookForSelectablePositionOnScreen(direction);
    int amountToScroll = amountToScroll(direction, nextSelectedPosition);
    ArrowScrollFocusResult focusResult = this.mItemsCanFocus ? arrowScrollFocused(direction) : null;
    if (focusResult != null) {
        nextSelectedPosition = focusResult.getSelectedPosition();
        amountToScroll = focusResult.getAmountToScroll();
    }
    if (focusResult != null) {
        needToRedraw = true;
    } else {
        needToRedraw = false;
    }
    if (nextSelectedPosition != -1) {
        boolean z;
        if (focusResult != null) {
            z = true;
        } else {
            z = false;
        }
        handleNewSelectionChange(selectedView, direction, nextSelectedPosition, z);
        setSelectedPositionInt(nextSelectedPosition);
        setNextSelectedPositionInt(nextSelectedPosition);
        selectedView = getSelectedView();
        selectedPos = nextSelectedPosition;
        if (this.mItemsCanFocus && focusResult == null) {
            focused = getFocusedChild();
            if (focused != null) {
                focused.clearFocus();
            }
        }
        needToRedraw = true;
        checkSelectionChanged();
    }
    if (amountToScroll > 0) {
        if (direction != 33) {
            amountToScroll = -amountToScroll;
        }
        scrollListItemsBy(amountToScroll);
        needToRedraw = true;
    }
    if (this.mItemsCanFocus && focusResult == null && selectedView != null && selectedView.hasFocus()) {
        focused = selectedView.findFocus();
        if (!isViewAncestorOf(focused, this) || distanceToView(focused) > 0) {
            focused.clearFocus();
        }
    }
    if (!(nextSelectedPosition != -1 || selectedView == null || isViewAncestorOf(selectedView, this))) {
        selectedView = null;
        hideSelector();
        this.mResurrectToPosition = -1;
    }
    if (!needToRedraw) {
        return false;
    }
    if (selectedView != null) {
        positionSelector(selectedPos, selectedView);
        this.mSelectedLeft = selectedView.getLeft();
    }
    if (!awakenScrollBars()) {
        invalidate();
    }
    invokeOnItemScrollListener();
    return true;
}