GTK: Draw bottom-aligned ntp themes on floating bookmark bar.

This is a simplified version of the windows code. There will be a follow-up patch to switch windows over to using this as well.

I ran into some trouble calculating the correct size of the tab contents. Punting on that for now, filed http://crbug.com/23907

BUG=22836
TEST=Tested on klassen, candies, karim rashid, tiesto, ratchet and clank, and jeff coons themes.

Review URL: http://codereview.chromium.org/255086

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@28215 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 79 insertions, 0 deletions

diff --git a/chrome/browser/ntp_background_util.cc b/chrome/browser/ntp_background_util.cc
new file mode 100644
index 0000000..1b02632
--- /dev/null
+++ b/chrome/browser/ntp_background_util.cc
@@ -0,0 +1,79 @@
+// Copyright (c) 2009 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 "chrome/browser/ntp_background_util.h"
+
+#include "app/gfx/canvas.h"
+#include "base/gfx/rect.h"
+#include "base/logging.h"
+#include "chrome/browser/browser_theme_provider.h"
+#include "grit/theme_resources.h"
+#include "skia/ext/skia_utils.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+
+namespace {
+
+void PaintThemeBackground(
+    gfx::Canvas* canvas, SkBitmap* ntp_background, int tiling, int alignment,
+    const gfx::Rect& area, int tab_contents_height) {
+  int x_pos = 0;
+  int y_pos = 0;
+  int width = area.width() + ntp_background->width();
+  int height = area.height() + ntp_background->height();
+
+  if (alignment & BrowserThemeProvider::ALIGN_BOTTOM)
+    y_pos += area.height() + tab_contents_height - ntp_background->height();
+
+  if (alignment & BrowserThemeProvider::ALIGN_RIGHT) {
+    x_pos += area.width() - ntp_background->width();
+  } else if (alignment & BrowserThemeProvider::ALIGN_LEFT) {
+    // no op
+  } else {  // ALIGN_CENTER
+    x_pos += area.width() / 2 - ntp_background->width() / 2;
+  }
+
+  if (tiling != BrowserThemeProvider::REPEAT &&
+      tiling != BrowserThemeProvider::REPEAT_X) {
+    width = ntp_background->width();
+  } else if (x_pos > 0) {
+    x_pos = x_pos % ntp_background->width() - ntp_background->width();
+  }
+
+  if (tiling != BrowserThemeProvider::REPEAT &&
+      tiling != BrowserThemeProvider::REPEAT_Y) {
+    height = ntp_background->height();
+  } else if (y_pos > 0) {
+    y_pos = y_pos % ntp_background->height() - ntp_background->height();
+  }
+
+  x_pos += area.x();
+  y_pos += area.y();
+
+  canvas->TileImageInt(*ntp_background, x_pos, y_pos, width, height);
+}
+
+}  // namespace
+
+// static
+void NtpBackgroundUtil::PaintBackgroundDetachedMode(
+    ThemeProvider* tp, gfx::Canvas* canvas, const gfx::Rect& area,
+    int tab_contents_height) {
+  // Draw the background to match the new tab page.
+  canvas->FillRectInt(tp->GetColor(BrowserThemeProvider::COLOR_NTP_BACKGROUND),
+                      area.x(), area.y(), area.width(), area.height());
+
+  if (tp->HasCustomImage(IDR_THEME_NTP_BACKGROUND)) {
+    int tiling = BrowserThemeProvider::NO_REPEAT;
+    tp->GetDisplayProperty(BrowserThemeProvider::NTP_BACKGROUND_TILING,
+                           &tiling);
+    int alignment;
+    if (tp->GetDisplayProperty(BrowserThemeProvider::NTP_BACKGROUND_ALIGNMENT,
+        &alignment)) {
+      SkBitmap* ntp_background = tp->GetBitmapNamed(IDR_THEME_NTP_BACKGROUND);
+
+      PaintThemeBackground(
+          canvas, ntp_background, tiling, alignment, area, tab_contents_height);
+    }
+  }
+}