[Android] Composited selection handle rendering

content/public/android/java/src/org/chromium/content/browser/input/SelectionHandleController.java

-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.content.browser.input;
-
-import android.view.View;
-
-import com.google.common.annotations.VisibleForTesting;
-
-import org.chromium.content.browser.PositionObserver;
-
-/**
- * CursorController for selecting a range of text.
- */
-public abstract class SelectionHandleController implements CursorController {
-
-    // The following constants match the ones in
-    // third_party/WebKit/public/web/WebTextDirection.h
-    private static final int TEXT_DIRECTION_DEFAULT = 0;
-    private static final int TEXT_DIRECTION_LTR = 1;
-    private static final int TEXT_DIRECTION_RTL = 2;
-
-    /** The cursor controller images, lazily created when shown. */
-    private HandleView mStartHandle, mEndHandle;
-
-    /** Whether handles should show automatically when text is selected. */
-    private boolean mAllowAutomaticShowing = true;
-
-    /** Whether selection anchors are active. */
-    private boolean mIsShowing;
-
-    private View mParent;
-
-    private int mFixedHandleX;
-    private int mFixedHandleY;
-
-    private PositionObserver mPositionObserver;
-
-    public SelectionHandleController(View parent, PositionObserver positionObserver) {
-        mParent = parent;
-        mPositionObserver = positionObserver;
-    }
-
-    /** Automatically show selection anchors when text is selected. */
-    public void allowAutomaticShowing() {
-        mAllowAutomaticShowing = true;
-    }
-
-    /** Hide selection anchors, and don't automatically show them. */
-    public void hideAndDisallowAutomaticShowing() {
-        hide();
-        mAllowAutomaticShowing = false;
-    }
-
-    @Override
-    public boolean isShowing() {
-        return mIsShowing;
-    }
-
-    @Override
-    public void hide() {
-        if (mIsShowing) {
-            if (mStartHandle != null) mStartHandle.hide();
-            if (mEndHandle != null) mEndHandle.hide();
-            mIsShowing = false;
-        }
-    }
-
-    void cancelFadeOutAnimation() {
-        hide();
-    }
-
-    /**
-     * Updates the selection for a movement of the given handle (which
-     * should be the start handle or end handle) to coordinates x,y.
-     * Note that this will not actually result in the handle moving to (x,y):
-     * selectBetweenCoordinates(x1,y1,x2,y2) will trigger the selection and set the
-     * actual coordinates later via set[Start|End]HandlePosition.
-     */
-    @Override
-    public void updatePosition(HandleView handle, int x, int y) {
-        selectBetweenCoordinates(mFixedHandleX, mFixedHandleY, x, y);
-    }
-
-    @Override
-    public void beforeStartUpdatingPosition(HandleView handle) {
-        HandleView fixedHandle = (handle == mStartHandle) ? mEndHandle : mStartHandle;
-        mFixedHandleX = fixedHandle.getAdjustedPositionX();
-        mFixedHandleY = fixedHandle.getLineAdjustedPositionY();
-    }
-
-    /**
-     * The concrete implementation must trigger a selection between the given
-     * coordinates and (possibly asynchronously) set the actual handle positions
-     * after the selection is made via set[Start|End]HandlePosition.
-     */
-    protected abstract void selectBetweenCoordinates(int x1, int y1, int x2, int y2);
-
-    /**
-     * @return true iff this controller is being used to move the selection start.
-     */
-    boolean isSelectionStartDragged() {
-        return mStartHandle != null && mStartHandle.isDragging();
-    }
-
-    /**
-     * @return true iff this controller is being used to drag either the selection start or end.
-     */
-    public boolean isDragging() {
-        return (mStartHandle != null && mStartHandle.isDragging()) ||
-               (mEndHandle != null && mEndHandle.isDragging());
-    }
-
-    @Override
-    public void onTouchModeChanged(boolean isInTouchMode) {
-        if (!isInTouchMode) {
-            hide();
-        }
-    }
-
-    @Override
-    public void onDetached() {}
-
-    /**
-     * Moves the start handle so that it points at the given coordinates.
-     * @param x The start handle position X in physical pixels.
-     * @param y The start handle position Y in physical pixels.
-     */
-    public void setStartHandlePosition(float x, float y) {
-        mStartHandle.positionAt((int) x, (int) y);
-    }
-
-    /**
-     * Moves the end handle so that it points at the given coordinates.
-     * @param x The end handle position X in physical pixels.
-     * @param y The end handle position Y in physical pixels.
-     */
-    public void setEndHandlePosition(float x, float y) {
-        mEndHandle.positionAt((int) x, (int) y);
-    }
-
-    /**
-     * If the handles are not visible, sets their visibility to View.VISIBLE and begins fading them
-     * in.
-     */
-    public void beginHandleFadeIn() {
-        mStartHandle.beginFadeIn();
-        mEndHandle.beginFadeIn();
-    }
-
-    /**
-     * Sets the start and end handles to the given visibility.
-     */
-    public void setHandleVisibility(int visibility) {
-        mStartHandle.setVisibility(visibility);
-        mEndHandle.setVisibility(visibility);
-    }
-
-    /**
-     * Shows the handles if allowed.
-     *
-     * @param startDir Direction (left/right) of start handle.
-     * @param endDir Direction (left/right) of end handle.
-     */
-    public void onSelectionChanged(int startDir, int endDir) {
-        if (mAllowAutomaticShowing) {
-            showHandles(startDir, endDir);
-        }
-    }
-
-    /**
-     * Sets both start and end position and show the handles.
-     * Note: this method does not trigger a selection, see
-     * selectBetweenCoordinates()
-     *
-     * @param startDir Direction (left/right) of start handle.
-     * @param endDir Direction (left/right) of end handle.
-     */
-    public void showHandles(int startDir, int endDir) {
-        createHandlesIfNeeded(startDir, endDir);
-        showHandlesIfNeeded();
-    }
-
-    @VisibleForTesting
-    public HandleView getStartHandleViewForTest() {
-        return mStartHandle;
-    }
-
-    @VisibleForTesting
-    public HandleView getEndHandleViewForTest() {
-        return mEndHandle;
-    }
-
-    private void createHandlesIfNeeded(int startDir, int endDir) {
-        if (mStartHandle == null) {
-            mStartHandle = new HandleView(this,
-                    startDir == TEXT_DIRECTION_RTL ? HandleView.RIGHT : HandleView.LEFT, mParent,
-                    mPositionObserver);
-        }
-        if (mEndHandle == null) {
-            mEndHandle = new HandleView(this,
-                    endDir == TEXT_DIRECTION_RTL ? HandleView.LEFT : HandleView.RIGHT, mParent,
-                    mPositionObserver);
-        }
-    }
-
-    private void showHandlesIfNeeded() {
-        if (!mIsShowing) {
-            mIsShowing = true;
-            mStartHandle.show();
-            mEndHandle.show();
-            setHandleVisibility(HandleView.VISIBLE);
-        }
-    }
-}