Show selection handles around selected text.

content/public/android/java/src/org/chromium/content/browser/HandleView.java

+// Copyright (c) 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;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.os.SystemClock;
+import android.util.TypedValue;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+import android.view.WindowManager;
+import android.view.View.OnClickListener;
+import android.view.ViewGroup.LayoutParams;
+import android.widget.PopupWindow;
+import android.widget.TextView;
+
+/**
+ * View that displays a selection or insertion handle for text editing.
+ */
+class HandleView extends View {
+    private Drawable mDrawable;
+    private final PopupWindow mContainer;
+    private int mPositionX;
+    private int mPositionY;
+    private final CursorController mController;
+    private boolean mIsDragging;
+    private float mTouchToWindowOffsetX;
+    private float mTouchToWindowOffsetY;
+    private float mHotspotX;
+    private float mHotspotY;
+    private int mLineOffsetY;
+    private int mHeight;
+    private int mLastParentX;
+    private int mLastParentY;
+    private float mDownPositionX, mDownPositionY;
+    private int mContainerPositionX, mContainerPositionY;
+    private long mTouchTimer;
+    private boolean mIsInsertionHandle = false;
+    private Runnable mLongPressCallback;
+
+    private View mParent;
+    private InsertionHandleController.PastePopupMenu mPastePopupWindow;
+
+    private final int mTextSelectHandleLeftRes;
+    private final int mTextSelectHandleRightRes;
+    private final int mTextSelectHandleRes;
+
+    private Drawable mSelectHandleLeft;
+    private Drawable mSelectHandleRight;
+    private Drawable mSelectHandleCenter;
+
+    private final int[] mTempCoords = new int[2];
+    private final Rect mTempRect = new Rect();
+
+    static final int LEFT = 0;
+    static final int CENTER = 1;
+    static final int RIGHT = 2;
+
+    // Number of dips to subtract from the handle's y position to give a suitable
+    // y coordinate for the corresponding text position. This is to compensate for the fact
+    // that the handle position is at the base of the line of text.
+    private static final float LINE_OFFSET_Y_DIP = 5.0f;
+
+    private static final int[] TEXT_VIEW_HANDLE_ATTRS = {
+        android.R.attr.textSelectHandleLeft,
+        android.R.attr.textSelectHandle,
+        android.R.attr.textSelectHandleRight,
+    };
+
+    HandleView(CursorController controller, int pos, View parent) {
+        super(parent.getContext());
+        Context context = parent.getContext();
+        mParent = parent;
+        mController = controller;
+        mContainer = new PopupWindow(context, null, android.R.attr.textSelectHandleWindowStyle);
+        mContainer.setSplitTouchEnabled(true);
+        mContainer.setClippingEnabled(false);
+
+        TypedArray a = context.obtainStyledAttributes(TEXT_VIEW_HANDLE_ATTRS);
+        mTextSelectHandleLeftRes = a.getResourceId(a.getIndex(LEFT), 0);
+        mTextSelectHandleRes = a.getResourceId(a.getIndex(CENTER), 0);
+        mTextSelectHandleRightRes = a.getResourceId(a.getIndex(RIGHT), 0);
+        a.recycle();
+
+        setOrientation(pos);
+
+        // Convert line offset dips to pixels.
+        mLineOffsetY = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
+                LINE_OFFSET_Y_DIP, context.getResources().getDisplayMetrics());
+    }
+
+    void setOrientation(int pos) {
+        int handleWidth;
+        switch (pos) {
+        case LEFT: {
+            if (mSelectHandleLeft == null) {
+                mSelectHandleLeft = getContext().getResources().getDrawable(
+                        mTextSelectHandleLeftRes);
+            }
+            mDrawable = mSelectHandleLeft;
+            handleWidth = mDrawable.getIntrinsicWidth();
+            mHotspotX = (handleWidth * 3) / 4;
+            break;
+        }
+
+        case RIGHT: {
+            if (mSelectHandleRight == null) {
+                mSelectHandleRight = getContext().getResources().getDrawable(
+                        mTextSelectHandleRightRes);
+            }
+            mDrawable = mSelectHandleRight;
+            handleWidth = mDrawable.getIntrinsicWidth();
+            mHotspotX = handleWidth / 4;
+            break;
+        }
+
+        case CENTER:
+        default: {
+            if (mSelectHandleCenter == null) {
+                mSelectHandleCenter = getContext().getResources().getDrawable(
+                        mTextSelectHandleRes);
+            }
+            mDrawable = mSelectHandleCenter;
+            handleWidth = mDrawable.getIntrinsicWidth();
+            mHotspotX = handleWidth / 2;
+            mIsInsertionHandle = true;
+            break;
+        }
+        }
+
+        final int handleHeight = mDrawable.getIntrinsicHeight();
+        mHotspotY = 0;
+        mHeight = handleHeight;
+        invalidate();
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        setMeasuredDimension(mDrawable.getIntrinsicWidth(),
+                mDrawable.getIntrinsicHeight());
+    }
+
+    void show() {
+        if (!isPositionVisible()) {
+            hide();
+            return;
+        }
+        mContainer.setContentView(this);
+        final int[] coords = mTempCoords;
+        mParent.getLocationInWindow(coords);
+        mContainerPositionX = coords[0] + mPositionX;
+        mContainerPositionY = coords[1] + mPositionY;
+        mContainer.showAtLocation(mParent, 0, mContainerPositionX, mContainerPositionY);
+
+        // Hide paste view when handle is moved on screen.
+        if (mPastePopupWindow != null) {
+            mPastePopupWindow.hide();
+        }
+    }
+
+    void hide() {
+        mIsDragging = false;
+        mContainer.dismiss();
+        if (mPastePopupWindow != null) {
+            mPastePopupWindow.hide();
+        }
+    }
+
+    boolean isShowing() {
+        return mContainer.isShowing();
+    }
+
+    private boolean isPositionVisible() {
+        // Always show a dragging handle.
+        if (mIsDragging) {
+            return true;
+        }
+
+        final Rect clip = mTempRect;
+        clip.left = 0;
+        clip.top = 0;
+        clip.right = mParent.getWidth();
+        clip.bottom = mParent.getHeight();
+
+        final ViewParent parent = mParent.getParent();
+        if (parent == null || !parent.getChildVisibleRect(mParent, clip, null)) {
+            return false;
+        }
+
+        final int[] coords = mTempCoords;
+        mParent.getLocationInWindow(coords);
+        final int posX = coords[0] + mPositionX + (int) mHotspotX;
+        final int posY = coords[1] + mPositionY + (int) mHotspotY;
+
+        return posX >= clip.left && posX <= clip.right &&
+                posY >= clip.top && posY <= clip.bottom;
+    }
+
+    void moveTo(int x, int y) {
+        mPositionX = x;
+        mPositionY = y;
+        if (isPositionVisible()) {
+            int[] coords = null;
+            if (mContainer.isShowing()) {
+                coords = mTempCoords;
+                mParent.getLocationInWindow(coords);
+                final int containerPositionX = coords[0] + mPositionX;
+                final int containerPositionY = coords[1] + mPositionY;
+
+                if (containerPositionX != mContainerPositionX ||
+                    containerPositionY != mContainerPositionY) {
+                    mContainerPositionX = containerPositionX;
+                    mContainerPositionY = containerPositionY;
+
+                    mContainer.update(mContainerPositionX, mContainerPositionY,
+                            getRight() - getLeft(), getBottom() - getTop());
+
+                    // Hide paste popup window as soon as a scroll occurs.
+                    if (mPastePopupWindow != null) {
+                        mPastePopupWindow.hide();
+                    }
+                }
+            } else {
+                show();
+            }
+
+            if (mIsDragging) {
+                if (coords == null) {
+                    coords = mTempCoords;
+                    mParent.getLocationInWindow(coords);
+                }
+                if (coords[0] != mLastParentX || coords[1] != mLastParentY) {
+                    mTouchToWindowOffsetX += coords[0] - mLastParentX;
+                    mTouchToWindowOffsetY += coords[1] - mLastParentY;
+                    mLastParentX = coords[0];
+                    mLastParentY = coords[1];
+                }
+                // Hide paste popup window as soon as the handle is dragged.
+                if (mPastePopupWindow != null) {
+                    mPastePopupWindow.hide();
+                }
+            }
+        } else {
+            hide();
+        }
+    }
+
+    @Override
+    protected void onDraw(Canvas c) {
+        mDrawable.setBounds(0, 0, getRight() - getLeft(), getBottom() - getTop());
+        mDrawable.draw(c);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent ev) {
+        switch (ev.getActionMasked()) {
+            case MotionEvent.ACTION_DOWN: {
+                mDownPositionX = ev.getRawX();
+                mDownPositionY = ev.getRawY();
+                mTouchToWindowOffsetX = mDownPositionX - mPositionX;
+                mTouchToWindowOffsetY = mDownPositionY - mPositionY;
+                final int[] coords = mTempCoords;
+                mParent.getLocationInWindow(coords);
+                mLastParentX = coords[0];
+                mLastParentY = coords[1];
+                mIsDragging = true;
+                mController.beforeStartUpdatingPosition(this);
+                mTouchTimer = SystemClock.uptimeMillis();
+                break;
+            }
+
+            case MotionEvent.ACTION_MOVE: {
+                updatePosition(ev.getRawX(), ev.getRawY());
+                break;
+            }
+
+            case MotionEvent.ACTION_UP:
+                if (mIsInsertionHandle) {
+                    long delay = SystemClock.uptimeMillis() - mTouchTimer;
+                    if (delay < ViewConfiguration.getTapTimeout()) {
+                        if (mPastePopupWindow != null && mPastePopupWindow.isShowing()) {
+                            // Tapping on the handle dismisses the displayed paste view,
+                            mPastePopupWindow.hide();
+                        } else {
+                            showPastePopupWindow();
+                        }
+                    }
+                }
+                mIsDragging = false;
+                break;
+
+            case MotionEvent.ACTION_CANCEL:
+                mIsDragging = false;
+                break;
+        }
+        return true;
+    }
+
+    boolean isDragging() {
+        return mIsDragging;
+    }
+
+    /**
+     * @return Returns the x position of the handle
+     */
+    int getPositionX() {
+        return mPositionX;
+    }
+
+    /**
+     * @return Returns the y position of the handle
+     */
+    int getPositionY() {
+        return mPositionY;
+    }
+
+    private void updatePosition(float rawX, float rawY) {
+        final float newPosX = rawX - mTouchToWindowOffsetX + mHotspotX;
+        final float newPosY = rawY - mTouchToWindowOffsetY + mHotspotY - mLineOffsetY;
+
+        mController.updatePosition(this, Math.round(newPosX), Math.round(newPosY));
+    }
+
+    void positionAt(int x, int y) {
+        moveTo((int)(x - mHotspotX), (int)(y - mHotspotY));
+    }
+
+    // Returns the x coordinate of the position that the handle appears to be pointing to.
+    int getAdjustedPositionX() {
+        return (int) (mPositionX + mHotspotX);
+    }
+
+    // Returns the y coordinate of the position that the handle appears to be pointing to.
+    int getAdjustedPositionY() {
+        return (int) (mPositionY + mHotspotY);
+    }
+
+    // Returns a suitable y coordinate for the text position corresponding to the handle.
+    // As the handle points to a position on the base of the line of text, this method
+    // returns a coordinate a small number of pixels higher (i.e. a slightly smaller number)
+    // than getAdjustedPositionY.
+    int getLineAdjustedPositionY() {
+        return (int) (mPositionY + mHotspotY - mLineOffsetY);
+    }
+
+    Drawable getDrawable() {
+        return mDrawable;
+    }
+
+    void showPastePopupWindow() {
+        InsertionHandleController ihc = (InsertionHandleController) mController;
+        if (mIsInsertionHandle && ihc.canPaste()) {
+            if (mPastePopupWindow == null) {
+                // Lazy initialization: create when actually shown only.
+                mPastePopupWindow = ihc.new PastePopupMenu();
+            }
+            mPastePopupWindow.show();
+        }
+    }
+}