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

4 files changed, 138 insertions, 35 deletions

diff --git a/chrome/browser/gtk/bookmark_bar_gtk.cc b/chrome/browser/gtk/bookmark_bar_gtk.cc
index 4197b21..33fa70e 100644
--- a/chrome/browser/gtk/bookmark_bar_gtk.cc
+++ b/chrome/browser/gtk/bookmark_bar_gtk.cc
@@ -6,6 +6,7 @@
 
 #include <vector>
 
+#include "app/gfx/canvas_paint.h"
 #include "app/gfx/text_elider.h"
 #include "app/gtk_dnd_util.h"
 #include "app/l10n_util.h"
@@ -30,8 +31,10 @@
 #include "chrome/browser/gtk/tabs/tab_strip_gtk.h"
 #include "chrome/browser/gtk/view_id_util.h"
 #include "chrome/browser/metrics/user_metrics.h"
+#include "chrome/browser/ntp_background_util.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/browser/tab_contents/tab_contents_view.h"
 #include "chrome/common/gtk_util.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/pref_names.h"
@@ -1017,12 +1020,12 @@ gboolean BookmarkBarGtk::OnEventBoxExpose(GtkWidget* widget,
   if (theme_provider->UseGtkTheme() && !bar->floating_)
     return FALSE;
 
-  cairo_t* cr = gdk_cairo_create(GDK_DRAWABLE(widget->window));
-  cairo_rectangle(cr, event->area.x, event->area.y,
-                  event->area.width, event->area.height);
-  cairo_clip(cr);
-
   if (!bar->floating_) {
+    cairo_t* cr = gdk_cairo_create(GDK_DRAWABLE(widget->window));
+    cairo_rectangle(cr, event->area.x, event->area.y,
+                    event->area.width, event->area.height);
+    cairo_clip(cr);
+
     // Paint the background theme image.
     gfx::Point tabstrip_origin =
         bar->tabstrip_origin_provider_->GetTabStripOriginForWidget(widget);
@@ -1038,40 +1041,30 @@ gboolean BookmarkBarGtk::OnEventBoxExpose(GtkWidget* widget,
         event->area.x + event->area.width - tabstrip_origin.x(),
         event->area.y + event->area.height - tabstrip_origin.y());
     cairo_fill(cr);
-  } else {
-    // Paint the NTP background. First set the background color.
-    GdkColor bg_color = theme_provider->UseGtkTheme() ? gfx::kGdkWhite :
-        theme_provider->GetGdkColor(BrowserThemeProvider::COLOR_NTP_BACKGROUND);
-    double bg_color_rgb[] = {
-        static_cast<double>(bg_color.red / 257) / 255.0,
-        static_cast<double>(bg_color.green / 257) / 255.0,
-        static_cast<double>(bg_color.blue / 257) / 255.0, };
-    cairo_set_source_rgb(cr, bg_color_rgb[0], bg_color_rgb[1], bg_color_rgb[2]);
-    cairo_rectangle(cr,
-        event->area.x,
-        event->area.y,
-        event->area.width,
-        event->area.height);
-    cairo_fill(cr);
 
-    // Now paint the image, if it exists.
-    // TODO(estade): handle different alignments.
-    if (theme_provider->HasCustomImage(IDR_THEME_NTP_BACKGROUND)) {
-      CairoCachedSurface* background = theme_provider->GetSurfaceNamed(
-          IDR_THEME_NTP_BACKGROUND, widget);
-      background->SetSource(cr, widget->allocation.x, widget->allocation.y);
-      cairo_pattern_set_extend(cairo_get_source(cr), CAIRO_EXTEND_REPEAT);
-      cairo_rectangle(cr,
-          event->area.x,
-          event->area.y,
-          event->area.width,
-          event->area.height);
-      cairo_fill(cr);
+    cairo_destroy(cr);
+  } else {
+    gfx::Size tab_contents_size;
+    Browser* browser = bar->browser_;
+    if (!browser) {
+      NOTREACHED();
+      return FALSE;
+    }
+    TabContents* tab_contents = browser->GetSelectedTabContents();
+    if (!tab_contents) {
+      NOTREACHED();
+      return FALSE;
     }
+    if (!tab_contents->view()) {
+      NOTREACHED();
+      return FALSE;
+    }
+    tab_contents_size = tab_contents->view()->GetContainerSize();
+    gfx::CanvasPaint canvas(event, true);
+    NtpBackgroundUtil::PaintBackgroundDetachedMode(theme_provider, &canvas,
+        gfx::Rect(widget->allocation), tab_contents_size.height());
   }
 
-  cairo_destroy(cr);
-
   return FALSE;  // Propagate expose to children.
 }
 
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);
+    }
+  }
+}
diff --git a/chrome/browser/ntp_background_util.h b/chrome/browser/ntp_background_util.h
new file mode 100644
index 0000000..9d2d656
--- /dev/null
+++ b/chrome/browser/ntp_background_util.h
@@ -0,0 +1,29 @@
+// 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.
+
+#ifndef CHROME_BROWSER_NTP_BACKGROUND_UTIL_H_
+#define CHROME_BROWSER_NTP_BACKGROUND_UTIL_H_
+
+class ThemeProvider;
+
+namespace gfx {
+class Canvas;
+class Rect;
+}
+
+class NtpBackgroundUtil {
+ public:
+  // Paints the NTP background on |canvas|. |area| is the area of the canvas
+  // that gets painted and also serves as the origin of the image (for top-
+  // aligned images). |tab_contents_height| is necessary for correctly painting
+  // bottom-aligned images since then the origin is the bottom of the web page.
+  static void PaintBackgroundDetachedMode(
+      ThemeProvider* tp, gfx::Canvas* canvas,
+      const gfx::Rect& area, int tab_contents_height);
+
+ private:
+  NtpBackgroundUtil() {}
+};
+
+#endif  // CHROME_BROWSER_NTP_BACKGROUND_UTIL_H_
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index 3a4bfd1..5e97e00 100755
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -1696,6 +1696,8 @@
         'browser/net/url_request_slow_http_job.h',
         'browser/net/url_request_tracking.cc',
         'browser/net/url_request_tracking.h',
+        'browser/ntp_background_util.cc',
+        'browser/ntp_background_util.h',
         'browser/omnibox_search_hint.cc',
         'browser/omnibox_search_hint.h',
         'browser/options_page_base.cc',