/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.text.method;
import android.graphics.Rect;
import android.text.Layout;
import android.text.Selection;
import android.text.Spannable;
import android.view.InputDevice;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;
/**
* A movement method that provides cursor movement and selection.
* Supports displaying the context menu on DPad Center.
*/
public class ArrowKeyMovementMethod extends BaseMovementMethod implements MovementMethod {
private static boolean isSelecting(Spannable buffer) {
return ((MetaKeyKeyListener.getMetaState(buffer, MetaKeyKeyListener.META_SHIFT_ON) == 1) ||
(MetaKeyKeyListener.getMetaState(buffer, MetaKeyKeyListener.META_SELECTING) != 0));
}
private static int getCurrentLineTop(Spannable buffer, Layout layout) {
return layout.getLineTop(layout.getLineForOffset(Selection.getSelectionEnd(buffer)));
}
private static int getPageHeight(TextView widget) {
// This calculation does not take into account the view transformations that
// may have been applied to the child or its containers. In case of scaling or
// rotation, the calculated page height may be incorrect.
final Rect rect = new Rect();
return widget.getGlobalVisibleRect(rect) ? rect.height() : 0;
}
@Override
protected boolean handleMovementKey(TextView widget, Spannable buffer, int keyCode,
int movementMetaState, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_CENTER:
if (KeyEvent.metaStateHasNoModifiers(movementMetaState)) {
if (event.getAction() == KeyEvent.ACTION_DOWN
&& event.getRepeatCount() == 0
&& MetaKeyKeyListener.getMetaState(buffer,
MetaKeyKeyListener.META_SELECTING, event) != 0) {
return widget.showContextMenu();
}
}
break;
}
return super.handleMovementKey(widget, buffer, keyCode, movementMetaState, event);
}
@Override
protected boolean left(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
if (isSelecting(buffer)) {
return Selection.extendLeft(buffer, layout);
} else {
return Selection.moveLeft(buffer, layout);
}
}
@Override
protected boolean right(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
if (isSelecting(buffer)) {
return Selection.extendRight(buffer, layout);
} else {
return Selection.moveRight(buffer, layout);
}
}
@Override
protected boolean up(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
if (isSelecting(buffer)) {
return Selection.extendUp(buffer, layout);
} else {
return Selection.moveUp(buffer, layout);
}
}
@Override
protected boolean down(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
if (isSelecting(buffer)) {
return Selection.extendDown(buffer, layout);
} else {
return Selection.moveDown(buffer, layout);
}
}
@Override
protected boolean pageUp(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
final boolean selecting = isSelecting(buffer);
final int targetY = getCurrentLineTop(buffer, layout) - getPageHeight(widget);
boolean handled = false;
for (;;) {
final int previousSelectionEnd = Selection.getSelectionEnd(buffer);
if (selecting) {
Selection.extendUp(buffer, layout);
} else {
Selection.moveUp(buffer, layout);
}
if (Selection.getSelectionEnd(buffer) == previousSelectionEnd) {
break;
}
handled = true;
if (getCurrentLineTop(buffer, layout) <= targetY) {
break;
}
}
return handled;
}
@Override
protected boolean pageDown(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
final boolean selecting = isSelecting(buffer);
final int targetY = getCurrentLineTop(buffer, layout) + getPageHeight(widget);
boolean handled = false;
for (;;) {
final int previousSelectionEnd = Selection.getSelectionEnd(buffer);
if (selecting) {
Selection.extendDown(buffer, layout);
} else {
Selection.moveDown(buffer, layout);
}
if (Selection.getSelectionEnd(buffer) == previousSelectionEnd) {
break;
}
handled = true;
if (getCurrentLineTop(buffer, layout) >= targetY) {
break;
}
}
return handled;
}
@Override
protected boolean top(TextView widget, Spannable buffer) {
if (isSelecting(buffer)) {
Selection.extendSelection(buffer, 0);
} else {
Selection.setSelection(buffer, 0);
}
return true;
}
@Override
protected boolean bottom(TextView widget, Spannable buffer) {
if (isSelecting(buffer)) {
Selection.extendSelection(buffer, buffer.length());
} else {
Selection.setSelection(buffer, buffer.length());
}
return true;
}
@Override
protected boolean lineStart(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
if (isSelecting(buffer)) {
return Selection.extendToLeftEdge(buffer, layout);
} else {
return Selection.moveToLeftEdge(buffer, layout);
}
}
@Override
protected boolean lineEnd(TextView widget, Spannable buffer) {
final Layout layout = widget.getLayout();
if (isSelecting(buffer)) {
return Selection.extendToRightEdge(buffer, layout);
} else {
return Selection.moveToRightEdge(buffer, layout);
}
}
/** {@hide} */
@Override
protected boolean leftWord(TextView widget, Spannable buffer) {
final int selectionEnd = widget.getSelectionEnd();
final WordIterator wordIterator = widget.getWordIterator();
wordIterator.setCharSequence(buffer, selectionEnd, selectionEnd);
return Selection.moveToPreceding(buffer, wordIterator, isSelecting(buffer));
}
/** {@hide} */
@Override
protected boolean rightWord(TextView widget, Spannable buffer) {
final int selectionEnd = widget.getSelectionEnd();
final WordIterator wordIterator = widget.getWordIterator();
wordIterator.setCharSequence(buffer, selectionEnd, selectionEnd);
return Selection.moveToFollowing(buffer, wordIterator, isSelecting(buffer));
}
@Override
protected boolean home(TextView widget, Spannable buffer) {
return lineStart(widget, buffer);
}
@Override
protected boolean end(TextView widget, Spannable buffer) {
return lineEnd(widget, buffer);
}
private static boolean isTouchSelecting(boolean isMouse, Spannable buffer) {
return isMouse ? Touch.isActivelySelecting(buffer) : isSelecting(buffer);
}
@Override
public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) {
int initialScrollX = -1;
int initialScrollY = -1;
final int action = event.getAction();
final boolean isMouse = event.isFromSource(InputDevice.SOURCE_MOUSE);
if (action == MotionEvent.ACTION_UP) {
initialScrollX = Touch.getInitialScrollX(widget, buffer);
initialScrollY = Touch.getInitialScrollY(widget, buffer);
}
boolean handled = Touch.onTouchEvent(widget, buffer, event);
if (widget.isFocused() && !widget.didTouchFocusSelect()) {
if (action == MotionEvent.ACTION_DOWN) {
// Capture the mouse pointer down location to ensure selection starts
// right under the mouse (and is not influenced by cursor location).
// The code below needs to run for mouse events.
// For touch events, the code should run only when selection is active.
if (isMouse || isTouchSelecting(isMouse, buffer)) {
int offset = widget.getOffsetForPosition(event.getX(), event.getY());
buffer.setSpan(LAST_TAP_DOWN, offset, offset, Spannable.SPAN_POINT_POINT);
// Disallow intercepting of the touch events, so that
// users can scroll and select at the same time.
// without this, users would get booted out of select
// mode once the view detected it needed to scroll.
widget.getParent().requestDisallowInterceptTouchEvent(true);
}
} else if (action == MotionEvent.ACTION_MOVE) {
// Cursor can be active at any location in the text while mouse pointer can start
// selection from a totally different location. Use LAST_TAP_DOWN span to ensure
// text selection will start from mouse pointer location.
if (isMouse && Touch.isSelectionStarted(buffer)) {
int offset = buffer.getSpanStart(LAST_TAP_DOWN);
Selection.setSelection(buffer, offset);
}
if (isTouchSelecting(isMouse, buffer) && handled) {
// Before selecting, make sure we've moved out of the "slop".
// handled will be true, if we're in select mode AND we're
// OUT of the slop
// Turn long press off while we're selecting. User needs to
// re-tap on the selection to enable long press
widget.cancelLongPress();
// Update selection as we're moving the selection area.
// Get the current touch position
int offset = widget.getOffsetForPosition(event.getX(), event.getY());
Selection.extendSelection(buffer, offset);
return true;
}
} else if (action == MotionEvent.ACTION_UP) {
// If we have scrolled, then the up shouldn't move the cursor,
// but we do need to make sure the cursor is still visible at
// the current scroll offset to avoid the scroll jumping later
// to show it.
if ((initialScrollY >= 0 && initialScrollY != widget.getScrollY()) ||
(initialScrollX >= 0 && initialScrollX != widget.getScrollX())) {
widget.moveCursorToVisibleOffset();
return true;
}
int offset = widget.getOffsetForPosition(event.getX(), event.getY());
if (isTouchSelecting(isMouse, buffer)) {
buffer.removeSpan(LAST_TAP_DOWN);
Selection.extendSelection(buffer, offset);
}
MetaKeyKeyListener.adjustMetaAfterKeypress(buffer);
MetaKeyKeyListener.resetLockedMeta(buffer);
return true;
}
}
return handled;
}
@Override
public boolean canSelectArbitrarily() {
return true;
}
@Override
public void initialize(TextView widget, Spannable text) {
Selection.setSelection(text, 0);
}
@Override
public void onTakeFocus(TextView view, Spannable text, int dir) {
if ((dir & (View.FOCUS_FORWARD | View.FOCUS_DOWN)) != 0) {
if (view.getLayout() == null) {
// This shouldn't be null, but do something sensible if it is.
Selection.setSelection(text, text.length());
}
} else {
Selection.setSelection(text, text.length());
}
}
public static MovementMethod getInstance() {
if (sInstance == null) {
sInstance = new ArrowKeyMovementMethod();
}
return sInstance;
}
private static final Object LAST_TAP_DOWN = new Object();
private static ArrowKeyMovementMethod sInstance;
}
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