1/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* vim: set ts=8 sts=2 et sw=2 tw=80: */
3/* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
5 * You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7#include "ViewRegion.h"
8#import <Cocoa/Cocoa.h>
9
10#include "nsChildView.h"
11
12using namespace mozilla;
13
14ViewRegion::~ViewRegion() {
15  for (size_t i = 0; i < mViews.Length(); i++) {
16    [mViews[i] removeFromSuperview];
17  }
18}
19
20bool ViewRegion::UpdateRegion(const LayoutDeviceIntRegion& aRegion,
21                              const nsChildView& aCoordinateConverter, NSView* aContainerView,
22                              NSView* (^aViewCreationCallback)()) {
23  if (mRegion == aRegion) {
24    return false;
25  }
26
27  // We need to construct the required region using as many EffectViews
28  // as necessary. We try to update the geometry of existing views if
29  // possible, or create new ones or remove old ones if the number of
30  // rects in the region has changed.
31
32  nsTArray<NSView*> viewsToRecycle = std::move(mViews);
33  // The mViews array is now empty.
34
35  size_t i = 0;
36  for (auto iter = aRegion.RectIter(); !iter.Done() || i < viewsToRecycle.Length(); i++) {
37    if (!iter.Done()) {
38      NSView* view = nil;
39      NSRect rect = aCoordinateConverter.DevPixelsToCocoaPoints(iter.Get());
40      if (i < viewsToRecycle.Length()) {
41        view = viewsToRecycle[i];
42      } else {
43        view = aViewCreationCallback();
44        [aContainerView addSubview:view];
45
46        // Now that the view is in the view hierarchy, it'll be kept alive by
47        // its superview, so we can drop our reference.
48        [view release];
49      }
50      if (!NSEqualRects(rect, [view frame])) {
51        [view setFrame:rect];
52      }
53      [view setNeedsDisplay:YES];
54      mViews.AppendElement(view);
55      iter.Next();
56    } else {
57      // Our new region is made of fewer rects than the old region, so we can
58      // remove this view. We only have a weak reference to it, so removing it
59      // from the view hierarchy will release it.
60      [viewsToRecycle[i] removeFromSuperview];
61    }
62  }
63
64  mRegion = aRegion;
65  return true;
66}
67