Login pod visual enhancements.

chrome/browser/chromeos/login/username_view.cc

 // Copyright (c) 2010 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/chromeos/login/username_view.h"
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/chromeos/login/rounded_view.h"
 #include "gfx/canvas.h"
 #include "gfx/canvas_skia.h"
 #include "gfx/rect.h"
+#include "third_party/skia/include/core/SkColorShader.h"
 #include "third_party/skia/include/core/SkComposeShader.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
 
+namespace chromeos {
+
 namespace {
 // Username label background color.
 const SkColor kLabelBackgoundColor = 0x55000000;
 // Holds margin to height ratio.
 const double kMarginRatio = 1.0 / 3.0;
+
+// Class that sets up half rounded rectangle (only the bottom corners are
+// rounded) as a clip region of the view.
+// For more info see the file "chrome/browser/chromeos/login/rounded_view.h".
+template<typename C>
+class HalfRoundedView : public RoundedView<C> {
+ public:
+  explicit HalfRoundedView(const std::wstring &text): RoundedView<C>(text) {
+  }
+
+ protected:
+  // Overrides ViewFilter.
+  virtual void DrawFrame(gfx::Canvas* canvas) {
+    // No frame is needed.
+  }
+
+  virtual SkRect GetViewRect() const {
+    gfx::Rect bounds = C::GetLocalBounds(false);
+    SkRect view_rect;
+    // The rectangle will be intersected with the bounds, so the correct half
+    // of the round rectangle will be obtained.
+    view_rect.iset(bounds.x(), bounds.y() - bounds.width(),
+                   bounds.x() + bounds.width(),
+                   bounds.y() + bounds.height());
+    return view_rect;
+  }
+};
+
 }  // namespace
-
-namespace chromeos {
-
 UsernameView::UsernameView(const std::wstring& username)
     : views::Label(username) {
 }
 
 void UsernameView::Paint(gfx::Canvas* canvas) {
   gfx::Rect bounds = GetLocalBounds(false);
   if (!text_image_.get())
     PaintUsername(bounds);
 
   DCHECK(bounds.size() ==
          gfx::Size(text_image_->width(), text_image_->height()));
 
+  canvas->DrawBitmapInt(*text_image_, bounds.x(), bounds.y());
+}
+
+void UsernameView::PaintUsername(const gfx::Rect& bounds) {
+  margin_width_ = bounds.height() * kMarginRatio;
+  gfx::CanvasSkia canvas(bounds.width(), bounds.height(), false);
+  // Draw transparent background.
+  canvas.drawColor(0);
+
+  // Calculate needed space.
+  int flags = gfx::Canvas::TEXT_ALIGN_LEFT |
+      gfx::Canvas::TEXT_VALIGN_MIDDLE |
+      gfx::Canvas::NO_ELLIPSIS;
+  int text_height, text_width;
+  gfx::CanvasSkia::SizeStringInt(WideToUTF16Hack(GetText()), font(),
+                                 &text_width, &text_height,
+                                 flags);
+  text_width += margin_width_;
+
+  // Also leave the right margin.
+  bool use_fading_for_text = text_width + margin_width_ >= bounds.width();
+
   // Only alpha channel counts.
   SkColor gradient_colors[2];
   gradient_colors[0] = 0xFFFFFFFF;
   gradient_colors[1] = 0x00FFFFFF;
 
-  int gradient_start = std::min(margin_width_ + text_width_,
-                                bounds.width() - bounds.height());
+  int gradient_start = use_fading_for_text ?
+                       bounds.width() - bounds.height() - margin_width_ :
+                       text_width;
+  int gradient_end = std::min(gradient_start + bounds.height(),
+                              bounds.width() - margin_width_);
 
   SkPoint gradient_borders[2];
   gradient_borders[0].set(SkIntToScalar(gradient_start), SkIntToScalar(0));
-  gradient_borders[1].set(SkIntToScalar(
-      gradient_start + bounds.height()), SkIntToScalar(0));
+  gradient_borders[1].set(SkIntToScalar(gradient_end), SkIntToScalar(0));
 
   SkShader* gradient_shader =
       SkGradientShader::CreateLinear(gradient_borders, gradient_colors, NULL, 2,
                                      SkShader::kClamp_TileMode, NULL);
-  SkShader* image_shader = SkShader::CreateBitmapShader(
-      *text_image_,
-      SkShader::kRepeat_TileMode,
-      SkShader::kRepeat_TileMode);
 
-  SkXfermode* mode = SkXfermode::Create(SkXfermode::kSrcIn_Mode);
-  SkShader* composite_shader = new SkComposeShader(gradient_shader,
-                                                   image_shader, mode);
-  gradient_shader->unref();
-  image_shader->unref();
+  if (!use_fading_for_text) {
+    // Draw the final background with the fading in the end.
+    SkShader* solid_shader = new SkColorShader(kLabelBackgoundColor);
+    SkXfermode* mode = SkXfermode::Create(SkXfermode::kSrcIn_Mode);
+    SkShader* composite_shader = new SkComposeShader(gradient_shader,
+                                                     solid_shader, mode);
+    gradient_shader->unref();
+    solid_shader->unref();
 
-  SkPaint paint;
-  paint.setAntiAlias(true);
-  paint.setFilterBitmap(true);
-  paint.setShader(composite_shader)->unref();
-  canvas->DrawRectInt(bounds.x(), bounds.y(),
-                      bounds.width(), bounds.height(), paint);
-}
+    SkPaint paint;
+    paint.setShader(composite_shader)->unref();
+    canvas.drawPaint(paint);
+  }
 
-void UsernameView::PaintUsername(const gfx::Rect& bounds) {
-  margin_width_ = bounds.height() * kMarginRatio;
-  gfx::CanvasSkia canvas(bounds.width(), bounds.height(), false);
-  // Draw background.
-  canvas.drawColor(kLabelBackgoundColor);
-  // Calculate needed space.
-  int flags = gfx::Canvas::TEXT_ALIGN_LEFT |
-      gfx::Canvas::TEXT_VALIGN_MIDDLE |
-      gfx::Canvas::NO_ELLIPSIS;
-  int text_height;
-  gfx::CanvasSkia::SizeStringInt(WideToUTF16Hack(GetText()), font(),
-                                 &text_width_, &text_height,
-                                 flags);
-  text_width_ = std::min(text_width_, bounds.width() - margin_width_);
   // Draw the text.
   // Note, direct call of the DrawStringInt method produces the green dots
   // along the text perimeter (when the label is place on the white background).
   SkColor kInvisibleHaloColor = 0x00000000;
   canvas.DrawStringWithHalo(GetText(), font(), GetColor(), kInvisibleHaloColor,
                             bounds.x() + margin_width_, bounds.y(),
-                            bounds.width() - margin_width_, bounds.height(),
+                            bounds.width() - 2 * margin_width_, bounds.height(),
                             flags);
 
   text_image_.reset(new SkBitmap(canvas.ExtractBitmap()));
-  text_image_->buildMipMap(false);
+
+  if (use_fading_for_text) {
+    // Fade out only the text in the end. Use regualar background.
+    canvas.drawColor(kLabelBackgoundColor, SkXfermode::kSrc_Mode);
+    SkShader* image_shader = SkShader::CreateBitmapShader(
+        *text_image_,
+        SkShader::kRepeat_TileMode,
+        SkShader::kRepeat_TileMode);
+    SkXfermode* mode = SkXfermode::Create(SkXfermode::kSrcIn_Mode);
+    SkShader* composite_shader = new SkComposeShader(gradient_shader,
+                                                     image_shader, mode);
+    gradient_shader->unref();
+    image_shader->unref();
+
+    SkPaint paint;
+    paint.setShader(composite_shader)->unref();
+    canvas.drawPaint(paint);
+    text_image_.reset(new SkBitmap(canvas.ExtractBitmap()));
+  }
+}
+
+UsernameView* UsernameView::CreateShapedUsernameView(
+    const std::wstring& username) {
+  return new HalfRoundedView<UsernameView>(username);
 }
 
 }  // namespace chromeos