1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "chrome/browser/chromeos/login/username_view.h"
6
7#include "base/logging.h"
8#include "base/utf_string_conversions.h"
9#include "chrome/browser/chromeos/login/rounded_view.h"
10#include "grit/generated_resources.h"
11#include "third_party/skia/include/core/SkColorShader.h"
12#include "third_party/skia/include/core/SkComposeShader.h"
13#include "third_party/skia/include/effects/SkGradientShader.h"
14#include "ui/base/l10n/l10n_util.h"
15#include "ui/base/resource/resource_bundle.h"
16#include "ui/gfx/canvas.h"
17#include "ui/gfx/canvas_skia.h"
18#include "ui/gfx/gtk_util.h"
19#include "ui/gfx/rect.h"
20
21namespace chromeos {
22
23namespace {
24// Username label background color.
25const SkColor kLabelBackgoundColor = 0x55000000;
26// Holds margin to height ratio.
27const double kMarginRatio = 1.0 / 3.0;
28// Holds the frame width for the small shaped username view.
29const SkScalar kSmallShapeFrameWidth = SkIntToScalar(1);
30
31// Class that sets up half rounded rectangle (only the bottom corners are
32// rounded) as a clip region of the view.
33// For more info see the file "chrome/browser/chromeos/login/rounded_view.h".
34template<typename C>
35class HalfRoundedView : public RoundedView<C> {
36 public:
37  HalfRoundedView(const std::wstring &text, bool use_small_shape)
38      : RoundedView<C>(text, use_small_shape) {
39  }
40
41 protected:
42  // Overrides ViewFilter.
43  virtual SkPath GetClipPath() const {
44    if (!C::use_small_shape()) {
45      return RoundedView<C>::GetClipPath();
46    } else {
47      SkPath path;
48      gfx::Rect frame_bounds = this->bounds();
49      frame_bounds.Inset(kSmallShapeFrameWidth, kSmallShapeFrameWidth,
50                   kSmallShapeFrameWidth, kSmallShapeFrameWidth);
51      path.addRect(SkIntToScalar(frame_bounds.x()),
52                   SkIntToScalar(frame_bounds.y()),
53                   SkIntToScalar(frame_bounds.x() + frame_bounds.width()),
54                   SkIntToScalar(frame_bounds.y() + frame_bounds.height()));
55      return path;
56    }
57  }
58
59  virtual void DrawFrame(gfx::Canvas* canvas) {
60    // No frame is needed.
61  }
62
63  virtual SkRect GetViewRect() const {
64    SkRect view_rect;
65    // The rectangle will be intersected with the bounds, so the correct half
66    // of the round rectangle will be obtained.
67    view_rect.iset(this->x(),
68                   this->y() - this->height(),
69                   this->x() + this->width(),
70                   this->y() + this->height());
71    return view_rect;
72  }
73};
74
75}  // namespace
76
77UsernameView::UsernameView(const std::wstring& username, bool use_small_shape)
78    : views::Label(username.empty()
79          ? UTF16ToWide(l10n_util::GetStringUTF16(IDS_GUEST)) : username),
80      use_small_shape_(use_small_shape),
81      is_guest_(username.empty()) {
82}
83
84void UsernameView::OnPaint(gfx::Canvas* canvas) {
85  gfx::Rect bounds = GetContentsBounds();
86  if (text_image_ == NULL)
87    PaintUsername(bounds);
88  DCHECK(text_image_ != NULL);
89  DCHECK(bounds.size() ==
90         gfx::Size(text_image_->width(), text_image_->height()));
91  canvas->DrawBitmapInt(*text_image_, bounds.x(), bounds.y());
92}
93
94// static
95UsernameView* UsernameView::CreateShapedUsernameView(
96    const std::wstring& username, bool use_small_shape) {
97  return new HalfRoundedView<UsernameView>(username, use_small_shape);
98}
99
100gfx::NativeCursor UsernameView::GetCursorForPoint(
101    ui::EventType event_type,
102    const gfx::Point& p) {
103  return use_small_shape_ ? gfx::GetCursor(GDK_HAND2) : NULL;
104}
105
106void UsernameView::PaintUsername(const gfx::Rect& bounds) {
107  margin_width_ = bounds.height() * kMarginRatio;
108  gfx::CanvasSkia canvas(bounds.width(), bounds.height(), false);
109  // Draw transparent background.
110  canvas.drawColor(0);
111
112  // Calculate needed space.
113  int flags = gfx::Canvas::TEXT_ALIGN_LEFT |
114      gfx::Canvas::TEXT_VALIGN_MIDDLE |
115      gfx::Canvas::NO_ELLIPSIS;
116  int text_height, text_width;
117  gfx::CanvasSkia::SizeStringInt(WideToUTF16Hack(GetText()), font(),
118                                 &text_width, &text_height,
119                                 flags);
120  text_width += margin_width_;
121
122  // Also leave the right margin.
123  bool use_fading_for_text = text_width + margin_width_ >= bounds.width();
124
125  // Only alpha channel counts.
126  SkColor gradient_colors[2];
127  gradient_colors[0] = 0xFFFFFFFF;
128  gradient_colors[1] = 0x00FFFFFF;
129
130  int gradient_start = use_fading_for_text ?
131                       bounds.width() - bounds.height() - margin_width_ :
132                       text_width;
133  int gradient_end = std::min(gradient_start + bounds.height(),
134                              bounds.width() - margin_width_);
135
136  SkPoint gradient_borders[2];
137  gradient_borders[0].set(SkIntToScalar(gradient_start), SkIntToScalar(0));
138  gradient_borders[1].set(SkIntToScalar(gradient_end), SkIntToScalar(0));
139
140  SkShader* gradient_shader =
141      SkGradientShader::CreateLinear(gradient_borders, gradient_colors, NULL, 2,
142                                     SkShader::kClamp_TileMode, NULL);
143
144  if (!use_fading_for_text) {
145    // Draw the final background with the fading in the end.
146    SkShader* solid_shader = new SkColorShader(kLabelBackgoundColor);
147    SkXfermode* mode = SkXfermode::Create(SkXfermode::kSrcIn_Mode);
148    SkShader* composite_shader = new SkComposeShader(gradient_shader,
149                                                     solid_shader, mode);
150    gradient_shader->unref();
151    solid_shader->unref();
152
153    SkPaint paint;
154    paint.setShader(composite_shader)->unref();
155    canvas.drawPaint(paint);
156  }
157
158  // Draw the text.
159  // Note, direct call of the DrawStringInt method produces the green dots
160  // along the text perimeter (when the label is place on the white background).
161  SkColor kInvisibleHaloColor = 0x00000000;
162  canvas.DrawStringWithHalo(WideToUTF16Hack(GetText()), font(), GetColor(),
163                            kInvisibleHaloColor, bounds.x() + margin_width_,
164                            bounds.y(), bounds.width() - 2 * margin_width_,
165                            bounds.height(), flags);
166
167  text_image_.reset(new SkBitmap(canvas.ExtractBitmap()));
168
169  if (use_fading_for_text) {
170    // Fade out only the text in the end. Use regular background.
171    canvas.drawColor(kLabelBackgoundColor, SkXfermode::kSrc_Mode);
172    SkShader* image_shader = SkShader::CreateBitmapShader(
173        *text_image_,
174        SkShader::kRepeat_TileMode,
175        SkShader::kRepeat_TileMode);
176    SkXfermode* mode = SkXfermode::Create(SkXfermode::kSrcIn_Mode);
177    SkShader* composite_shader = new SkComposeShader(gradient_shader,
178                                                     image_shader, mode);
179    gradient_shader->unref();
180    image_shader->unref();
181
182    SkPaint paint;
183    paint.setShader(composite_shader)->unref();
184    canvas.drawPaint(paint);
185    text_image_.reset(new SkBitmap(canvas.ExtractBitmap()));
186  }
187}
188
189void UsernameView::OnLocaleChanged() {
190  if (is_guest_) {
191    SetText(UTF16ToWide(l10n_util::GetStringUTF16(IDS_GUEST)));
192  }
193  // Repaint because the font may have changed.
194  text_image_.reset();
195  SchedulePaint();
196}
197
198}  // namespace chromeos
199