Message center re-organized

ui/views/shadow_border.cc

+// Copyright (c) 2013 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.
+
+#include "ui/views/shadow_border.h"
+
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/insets.h"
+#include "ui/gfx/shadow_value.h"
+#include "ui/gfx/skia_util.h"
+
+namespace views {
+
+ShadowBorder::ShadowBorder(int blur,
+                           SkColor color,
+                           int vertical_offset,
+                           int horizontal_offset)
+    : views::Border(),
+      blur_(blur),
+      color_(color),
+      vertical_offset_(vertical_offset),
+      horizontal_offset_(horizontal_offset) {}
+
+ShadowBorder::~ShadowBorder() {}
+
+void ShadowBorder::Paint(const views::View& view, gfx::Canvas* canvas) {
+  gfx::Rect bounds(view.size());
+
+  if (bounds != cache_bounds_ || !cached_border_.get()) {
+    cache_bounds_ = bounds;
+
+    // We cache the border since re-painting a shadow looper on every paint call
+    // may yield poor performance. So we draw the border on a separate canvas
+    // and cache the bitmap of the drawn border.
+    gfx::Canvas border_canvas(view.size(), canvas->scale_factor(), false);
+
+    SkPaint paint;
+    std::vector<gfx::ShadowValue> shadows;
+    shadows.push_back(gfx::ShadowValue(gfx::Point(), blur_, color_));
+    skia::RefPtr<SkDrawLooper> looper = gfx::CreateShadowDrawLooper(shadows);
+    paint.setLooper(looper.get());
+    paint.setColor(SK_ColorTRANSPARENT);
+    paint.setStrokeJoin(SkPaint::kRound_Join);
+    bounds.Inset(gfx::Insets(blur_ / 2, blur_ / 2, blur_ / 2, blur_ / 2));
+    border_canvas.DrawRect(bounds, paint);
+
+    cached_border_.reset(new gfx::ImageSkia(border_canvas.ExtractImageRep()));

[dewittj, 2013/07/15 18:38:58]

Does this cache an image the size of the contained view?  I wonder if storing 4
separate images, one for each edge, would be better.  Message center can be the
height of the screen currently, so this would mean storing a 2000x380 or so
image, which is not a negligible size (around 18MB RAM uncompressed).

[sidharthms, 2013/07/15 23:16:37]

Removed for now. I'll submit a separate cl to add caching.

On 2013/07/15 18:38:58, dewittj wrote:

+  }
+  canvas->DrawImageInt(*cached_border_.get(), 0, 0);
+}
+
+gfx::Insets ShadowBorder::GetInsets() const {
+  return gfx::Insets(blur_ / 2 - vertical_offset_,
+                     blur_ / 2 - horizontal_offset_,
+                     blur_ / 2 + vertical_offset_,
+                     blur_ / 2 + horizontal_offset_);
+}
+
+}  // namespace views