Better Linux ChromeCanvas text drawing, using Pango.

Skia doesn't current support any form of text layout (ellipsizing, etc).  We
use Pango / Cairo to draw our text on the surface.  Also moved the non-flags
version of DrawStringInt into the share chrome_canvas.cc.  Stubbed out the
SizeStringInt(), I haven't seen it used on Linux, and it would be wrong.

Review URL: http://codereview.chromium.org/62053


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@13159 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 116 insertions, 74 deletions

diff --git a/chrome/common/gfx/chrome_canvas.cc b/chrome/common/gfx/chrome_canvas.cc
index f439680..647983e 100644
--- a/chrome/common/gfx/chrome_canvas.cc
+++ b/chrome/common/gfx/chrome_canvas.cc
@@ -206,6 +206,15 @@ void ChromeCanvas::DrawBitmapInt(const SkBitmap& bitmap, int src_x, int src_y,
   drawRect(dest_rect, p);
 }
 
+void ChromeCanvas::DrawStringInt(const std::wstring& text,
+                                 const ChromeFont& font,
+                                 const SkColor& color,
+                                 int x, int y,
+                                 int w, int h) {
+  DrawStringInt(text, font, color, x, y, w, h,
+                l10n_util::DefaultCanvasTextAlignment());
+}
+
 void ChromeCanvas::TileImageInt(const SkBitmap& bitmap,
                                 int x, int y, int w, int h) {
   TileImageInt(bitmap, 0, 0, x, y, w, h);
diff --git a/chrome/common/gfx/chrome_canvas_linux.cc b/chrome/common/gfx/chrome_canvas_linux.cc
new file mode 100644
index 0000000..93a32f7
--- /dev/null
+++ b/chrome/common/gfx/chrome_canvas_linux.cc
@@ -0,0 +1,107 @@
+// 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/common/gfx/chrome_canvas.h"
+
+#include <pango/pango.h>
+
+#include "base/gfx/rect.h"
+#include "base/logging.h"
+#include "base/string_util.h"
+#include "chrome/common/gfx/chrome_font.h"
+
+namespace {
+
+// Returns a new pango font, free with pango_font_description_free().
+PangoFontDescription* PangoFontFromChromeFont(const ChromeFont& chrome_font) {
+  ChromeFont font = chrome_font;  // Copy so we can call non-const methods.
+  PangoFontDescription* pfd = pango_font_description_new();
+  pango_font_description_set_family(pfd, WideToUTF8(font.FontName()).c_str());
+  pango_font_description_set_size(pfd, font.FontSize() * PANGO_SCALE);
+
+  switch (font.style()) {
+    case ChromeFont::NORMAL:
+      // Nothing to do, should already be PANGO_STYLE_NORMAL.
+      break;
+    case ChromeFont::BOLD:
+      pango_font_description_set_weight(pfd, PANGO_WEIGHT_BOLD);
+      break;
+    case ChromeFont::ITALIC:
+      pango_font_description_set_style(pfd, PANGO_STYLE_ITALIC);
+      break;
+    case ChromeFont::UNDERLINED:
+      // TODO(deanm): How to do underlined?  Where do we use it?  Probably have
+      // to paint it ourselves, see pango_font_metrics_get_underline_position.
+      break;
+  }
+
+  return pfd;
+}
+
+}  // namespace
+
+ChromeCanvas::ChromeCanvas(int width, int height, bool is_opaque)
+    : skia::PlatformCanvasLinux(width, height, is_opaque) {
+}
+
+ChromeCanvas::ChromeCanvas() : skia::PlatformCanvasLinux() {
+}
+
+ChromeCanvas::~ChromeCanvas() {
+}
+
+// static
+void ChromeCanvas::SizeStringInt(const std::wstring& text,
+                                 const ChromeFont& font,
+                                 int* width, int* height, int flags) {
+  NOTIMPLEMENTED();
+}
+
+
+void ChromeCanvas::DrawStringInt(const std::wstring& text,
+                                 const ChromeFont& font,
+                                 const SkColor& color, int x, int y, int w,
+                                 int h, int flags) {
+  cairo_surface_t* surface = beginPlatformPaint();
+  cairo_t* cr = cairo_create(surface);
+  PangoLayout* layout = pango_cairo_create_layout(cr);
+
+  cairo_set_source_rgb(cr,
+                       SkColorGetR(color) / 255.0,
+                       SkColorGetG(color) / 255.0,
+                       SkColorGetB(color) / 255.0);
+
+  // TODO(deanm): Implement the rest of the ChromeCanvas flags.
+  if (!(flags & ChromeCanvas::NO_ELLIPSIS))
+    pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
+
+  pango_layout_set_width(layout, w * PANGO_SCALE);
+  pango_layout_set_height(layout, h * PANGO_SCALE);
+
+  std::string utf8 = WideToUTF8(text);
+  pango_layout_set_text(layout, utf8.data(), utf8.size());
+
+  PangoFontDescription* desc = PangoFontFromChromeFont(font);
+  pango_layout_set_font_description(layout, desc);
+  pango_font_description_free(desc);
+
+  int width, height;
+  pango_layout_get_size(layout, &width, &height);
+
+  if (flags & ChromeCanvas::TEXT_VALIGN_TOP) {
+    // Cairo should draw from the top left corner already.
+  } else if (flags & ChromeCanvas::TEXT_VALIGN_BOTTOM) {
+    y = y + (h - (height / PANGO_SCALE));
+  } else {
+    // Vertically centered.
+    y = y + ((h - (height / PANGO_SCALE)) / 2);
+  }
+
+  cairo_move_to(cr, x, y);
+  pango_cairo_show_layout(cr, layout);
+
+  g_object_unref(layout);
+  cairo_destroy(cr);
+  // NOTE: beginPlatformPaint returned its surface, we shouldn't destroy it.
+}
diff --git a/chrome/common/gfx/chrome_canvas_skia.cc b/chrome/common/gfx/chrome_canvas_skia.cc
deleted file mode 100644
index b3b64d7..0000000
--- a/chrome/common/gfx/chrome_canvas_skia.cc
+++ /dev/null
@@ -1,65 +0,0 @@
-// Copyright (c) 2006-2008 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/common/gfx/chrome_canvas.h"
-
-#include <limits>
-
-#include "base/gfx/rect.h"
-#include "base/sys_string_conversions.h"
-#include "skia/include/SkShader.h"
-#include "skia/include/SkPaint.h"
-#include "chrome/common/gfx/chrome_font.h"
-#include "chrome/common/l10n_util.h"
-
-ChromeCanvas::ChromeCanvas(int width, int height, bool is_opaque)
-    : skia::PlatformCanvasLinux(width, height, is_opaque) {
-}
-
-ChromeCanvas::ChromeCanvas() : skia::PlatformCanvasLinux() {
-}
-
-ChromeCanvas::~ChromeCanvas() {
-}
-
-// static
-void ChromeCanvas::SizeStringInt(const std::wstring& text,
-                                 const ChromeFont& font,
-                                 int* width, int* height, int flags) {
-  // TODO(port): @flags is currently ignored
-  SkPaint paint;
-  font.PaintSetup(&paint);
-
-  const std::string utf8(base::SysWideToUTF8(text));
-  paint.setTextEncoding(SkPaint::kUTF8_TextEncoding);
-  SkRect bounds;
-  paint.measureText(utf8.data(), utf8.size(), &bounds);
-
-  *width = bounds.width();
-  *height = bounds.height();
-}
-
-void ChromeCanvas::DrawStringInt(const std::wstring& text,
-                                 const ChromeFont& font,
-                                 const SkColor& color, int x, int y, int w,
-                                 int h, int flags) {
-  // TODO(port): @flags, @w and @h are currently ignored
-  SkPaint paint;
-  font.PaintSetup(&paint);
-
-  const std::string utf8(base::SysWideToUTF8(text));
-  paint.setTextEncoding(SkPaint::kUTF8_TextEncoding);
-  paint.setColor(color);
-
-  drawText(utf8.data(), utf8.size(), x, y, paint);
-}
-
-void ChromeCanvas::DrawStringInt(const std::wstring& text,
-                                 const ChromeFont& font,
-                                 const SkColor& color,
-                                 int x, int y,
-                                 int w, int h) {
-  DrawStringInt(text, font, color, x, y, w, h,
-                l10n_util::DefaultCanvasTextAlignment());
-}
diff --git a/chrome/common/gfx/chrome_canvas_win.cc b/chrome/common/gfx/chrome_canvas_win.cc
index f6db09b..38446ca 100644
--- a/chrome/common/gfx/chrome_canvas_win.cc
+++ b/chrome/common/gfx/chrome_canvas_win.cc
@@ -182,15 +182,6 @@ void ChromeCanvas::DrawStringInt(const std::wstring& text, HFONT font,
 void ChromeCanvas::DrawStringInt(const std::wstring& text,
                                  const ChromeFont& font,
                                  const SkColor& color,
-                                 int x, int y,
-                                 int w, int h) {
-  DrawStringInt(text, font, color, x, y, w, h,
-                l10n_util::DefaultCanvasTextAlignment());
-}
-
-void ChromeCanvas::DrawStringInt(const std::wstring& text,
-                                 const ChromeFont& font,
-                                 const SkColor& color,
                                  int x, int y, int w, int h, int flags) {
   DrawStringInt(text, font.hfont(), color, x, y, w, h, flags);
 }