[Android] Composited selection handle rendering

content/public/android/java/src/org/chromium/content/browser/input/PastePopupMenu.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.content.Context;
+import android.content.res.TypedArray;
+import android.util.TypedValue;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.ViewGroup;
+import android.view.ViewGroup.LayoutParams;
+import android.widget.PopupWindow;
+
+/**
+ * Paste popup implementation based on TextView.PastePopupMenu.
+ */
+public class PastePopupMenu implements OnClickListener {
+    private final View mParent;
+    private final PastePopupMenuDelegate mDelegate;
+    private final Context mContext;
+    private final PopupWindow mContainer;
+    private int mRawPositionX;
+    private int mRawPositionY;
+    private int mPositionX;
+    private int mPositionY;
+    private final View[] mPasteViews;
+    private final int[] mPasteViewLayouts;
+    private final int mLineOffsetY;
+    private final int mWidthOffsetX;
+
+    /**
+     * Provider of paste functionality for the given popup.
+     */
+    public interface PastePopupMenuDelegate {
+        /**
+         * Called to initiate a paste after the popup has been tapped.
+         */
+        void paste();
+
+        /**
+         * @return true iff content can be pasted to a focused editable region.
+         */
+        boolean canPaste();
+    }
+
+    public PastePopupMenu(View parent, PastePopupMenuDelegate delegate) {
+        mParent = parent;
+        mDelegate = delegate;
+        mContext = parent.getContext();
+        mContainer = new PopupWindow(mContext, null,
+                android.R.attr.textSelectHandleWindowStyle);
+        mContainer.setSplitTouchEnabled(true);
+        mContainer.setClippingEnabled(false);
+        mContainer.setAnimationStyle(0);
+
+        mContainer.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
+        mContainer.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
+
+        final int[] POPUP_LAYOUT_ATTRS = {
+            android.R.attr.textEditPasteWindowLayout,
+            android.R.attr.textEditNoPasteWindowLayout,
+            android.R.attr.textEditSidePasteWindowLayout,
+            android.R.attr.textEditSideNoPasteWindowLayout,
+        };
+
+        mPasteViews = new View[POPUP_LAYOUT_ATTRS.length];
+        mPasteViewLayouts = new int[POPUP_LAYOUT_ATTRS.length];
+
+        TypedArray attrs = mContext.getTheme().obtainStyledAttributes(POPUP_LAYOUT_ATTRS);
+        for (int i = 0; i < attrs.length(); ++i) {
+            mPasteViewLayouts[i] = attrs.getResourceId(attrs.getIndex(i), 0);
+        }
+        attrs.recycle();
+
+        // Convert line offset dips to pixels.
+        mLineOffsetY = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
+                5.0f, mContext.getResources().getDisplayMetrics());
+        mWidthOffsetX = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
+                30.0f, mContext.getResources().getDisplayMetrics());
+    }
+
+    /**
+     * Shows the paste popup at an appropriate location relative to the specified position.
+     */
+    public void showAt(int x, int y) {
+        if (!canPaste()) return;
+        updateContent(true);
+        positionAt(x, y);
+    }
+
+    /**
+     * Hides the paste popup.
+     */
+    public void hide() {
+        mContainer.dismiss();
+    }
+
+    /**
+     * @return Whether the popup is active and showing.
+     */
+    public boolean isShowing() {
+        return mContainer.isShowing();
+    }
+
+    @Override
+    public void onClick(View v) {
+        if (canPaste()) {
+            paste();
+        }
+        hide();
+    }
+
+    private void positionAt(int x, int y) {
+        if (mRawPositionX == x && mRawPositionY == y && isShowing()) return;
+        mRawPositionX = x;
+        mRawPositionY = y;
+
+        View contentView = mContainer.getContentView();
+        int width = contentView.getMeasuredWidth();
+        int height = contentView.getMeasuredHeight();
+
+        mPositionX = (int) (x - width / 2.0f);
+        mPositionY = y - height - mLineOffsetY;
+
+        final int[] coords = new int[2];
+        mParent.getLocationInWindow(coords);
+        coords[0] += mPositionX;
+        coords[1] += mPositionY;
+
+        final int screenWidth = mContext.getResources().getDisplayMetrics().widthPixels;
+        if (coords[1] < 0) {
+            updateContent(false);
+            // Update dimensions from new view
+            contentView = mContainer.getContentView();
+            width = contentView.getMeasuredWidth();
+            height = contentView.getMeasuredHeight();
+
+            // Vertical clipping, move under edited line and to the side of insertion cursor
+            // TODO bottom clipping in case there is no system bar
+            coords[1] += height;
+            coords[1] += mLineOffsetY;
+
+            // Move to right hand side of insertion cursor by default. TODO RTL text.
+            final int handleHalfWidth = mWidthOffsetX / 2;
+
+            if (x + width < screenWidth) {
+                coords[0] += handleHalfWidth + width / 2;
+            } else {
+                coords[0] -= handleHalfWidth + width / 2;
+            }
+        } else {
+            // Horizontal clipping
+            coords[0] = Math.max(0, coords[0]);
+            coords[0] = Math.min(screenWidth - width, coords[0]);
+        }
+
+        mContainer.showAtLocation(mParent, Gravity.NO_GRAVITY, coords[0], coords[1]);
+    }
+
+    private int viewIndex(boolean onTop) {
+        return (onTop ? 0 : 1 << 1) + (canPaste() ? 0 : 1 << 0);
+    }
+
+    private void updateContent(boolean onTop) {
+        final int viewIndex = viewIndex(onTop);
+        View view = mPasteViews[viewIndex];
+
+        if (view == null) {
+            final int layout = mPasteViewLayouts[viewIndex];
+            LayoutInflater inflater = (LayoutInflater) mContext.
+                getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+            if (inflater != null) {
+                view = inflater.inflate(layout, null);
+            }
+
+            if (view == null) {
+                throw new IllegalArgumentException("Unable to inflate TextEdit paste window");
+            }
+
+            final int size = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
+            view.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
+                    ViewGroup.LayoutParams.WRAP_CONTENT));
+            view.measure(size, size);
+
+            view.setOnClickListener(this);
+
+            mPasteViews[viewIndex] = view;
+        }
+
+        mContainer.setContentView(view);
+    }
+
+    private boolean canPaste() {
+        return mDelegate.canPaste();
+    }
+
+    private void paste() {
+        mDelegate.paste();
+    }
+}