ui/views/controls/image_view.cc

   1 // Copyright (c) 2012 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 "ui/views/controls/image_view.h"
   6
   7 #include "base/logging.h"
   8 #include "base/strings/utf_string_conversions.h"
   9 #include "third_party/skia/include/core/SkPaint.h"
  10 #include "ui/accessibility/ax_view_state.h"
  11 #include "ui/gfx/canvas.h"
  12 #include "ui/gfx/geometry/insets.h"
  13 #include "ui/views/painter.h"
  14
  15 namespace views {
  16
  17 namespace {
  18
  19 // Returns the pixels for the bitmap in |image| at scale |image_scale|.
  20 void* GetBitmapPixels(const gfx::ImageSkia& img, float image_scale) {
  21   DCHECK_NE(0.0f, image_scale);
  22   const SkBitmap& bitmap = img.GetRepresentation(image_scale).sk_bitmap();
  23   SkAutoLockPixels pixel_lock(bitmap);
  24   return bitmap.getPixels();
  25 }
  26
  27 }  // namespace
  28
  29 // static
  30 const char ImageView::kViewClassName[] = "ImageView";
  31
  32 ImageView::ImageView()
  33     : image_size_set_(false),
  34       horiz_alignment_(CENTER),
  35       vert_alignment_(CENTER),
  36       interactive_(true),
  37       last_paint_scale_(0.f),
  38       last_painted_bitmap_pixels_(NULL),
  39       focus_painter_(Painter::CreateDashedFocusPainter()) {
  40 }
  41
  42 ImageView::~ImageView() {
  43 }
  44
  45 void ImageView::SetImage(const gfx::ImageSkia& img) {
  46   if (IsImageEqual(img))
  47     return;
  48
  49   last_painted_bitmap_pixels_ = NULL;
  50   gfx::Size pref_size(GetPreferredSize());
  51   image_ = img;
  52   if (pref_size != GetPreferredSize())
  53     PreferredSizeChanged();
  54   SchedulePaint();
  55 }
  56
  57 void ImageView::SetImage(const gfx::ImageSkia* image_skia) {
  58   if (image_skia) {
  59     SetImage(*image_skia);
  60   } else {
  61     gfx::ImageSkia t;
  62     SetImage(t);
  63   }
  64 }
  65
  66 const gfx::ImageSkia& ImageView::GetImage() {
  67   return image_;
  68 }
  69
  70 void ImageView::SetImageSize(const gfx::Size& image_size) {
  71   image_size_set_ = true;
  72   image_size_ = image_size;
  73   PreferredSizeChanged();
  74 }
  75
  76 bool ImageView::GetImageSize(gfx::Size* image_size) const {
  77   DCHECK(image_size);
  78   if (image_size_set_)
  79     *image_size = image_size_;
  80   return image_size_set_;
  81 }
  82
  83 gfx::Rect ImageView::GetImageBounds() const {
  84   gfx::Size image_size(image_size_set_ ?
  85     image_size_ : gfx::Size(image_.width(), image_.height()));
  86   return gfx::Rect(ComputeImageOrigin(image_size), image_size);
  87 }
  88
  89 void ImageView::ResetImageSize() {
  90   image_size_set_ = false;
  91 }
  92
  93 void ImageView::SetFocusPainter(scoped_ptr<Painter> focus_painter) {
  94   focus_painter_ = focus_painter.Pass();
  95 }
  96
  97 gfx::Size ImageView::GetPreferredSize() const {
  98   gfx::Insets insets = GetInsets();
  99   if (image_size_set_) {
 100     gfx::Size image_size;
 101     GetImageSize(&image_size);
 102     image_size.Enlarge(insets.width(), insets.height());
 103     return image_size;
 104   }
 105   return gfx::Size(image_.width() + insets.width(),
 106                    image_.height() + insets.height());
 107 }
 108
 109 bool ImageView::IsImageEqual(const gfx::ImageSkia& img) const {
 110   // Even though we copy ImageSkia in SetImage() the backing store
 111   // (ImageSkiaStorage) is not copied and may have changed since the last call
 112   // to SetImage(). The expectation is that SetImage() with different pixels is
 113   // treated as though the image changed. For this reason we compare not only
 114   // the backing store but also the pixels of the last image we painted.
 115   return image_.BackedBySameObjectAs(img) &&
 116       last_paint_scale_ != 0.0f &&
 117       last_painted_bitmap_pixels_ == GetBitmapPixels(img, last_paint_scale_);
 118 }
 119
 120 gfx::Point ImageView::ComputeImageOrigin(const gfx::Size& image_size) const {
 121   gfx::Insets insets = GetInsets();
 122
 123   int x;
 124   // In order to properly handle alignment of images in RTL locales, we need
 125   // to flip the meaning of trailing and leading. For example, if the
 126   // horizontal alignment is set to trailing, then we'll use left alignment for
 127   // the image instead of right alignment if the UI layout is RTL.
 128   Alignment actual_horiz_alignment = horiz_alignment_;
 129   if (base::i18n::IsRTL() && (horiz_alignment_ != CENTER))
 130     actual_horiz_alignment = (horiz_alignment_ == LEADING) ? TRAILING : LEADING;
 131   switch (actual_horiz_alignment) {
 132     case LEADING:  x = insets.left();                                 break;
 133     case TRAILING: x = width() - insets.right() - image_size.width(); break;
 134     case CENTER:   x = (width() - image_size.width()) / 2;            break;
 135     default:       NOTREACHED(); x = 0;                               break;
 136   }
 137
 138   int y;
 139   switch (vert_alignment_) {
 140     case LEADING:  y = insets.top();                                     break;
 141     case TRAILING: y = height() - insets.bottom() - image_size.height(); break;
 142     case CENTER:   y = (height() - image_size.height()) / 2;             break;
 143     default:       NOTREACHED(); y = 0;                                  break;
 144   }
 145
 146   return gfx::Point(x, y);
 147 }
 148
 149 void ImageView::OnFocus() {
 150   View::OnFocus();
 151   if (focus_painter_.get())
 152     SchedulePaint();
 153 }
 154
 155 void ImageView::OnBlur() {
 156   View::OnBlur();
 157   if (focus_painter_.get())
 158     SchedulePaint();
 159 }
 160
 161 void ImageView::OnPaint(gfx::Canvas* canvas) {
 162   View::OnPaint(canvas);
 163   OnPaintImage(canvas);
 164   Painter::PaintFocusPainter(this, canvas, focus_painter_.get());
 165 }
 166
 167 void ImageView::GetAccessibleState(ui::AXViewState* state) {
 168   state->role = ui::AX_ROLE_IMAGE;
 169   state->name = tooltip_text_;
 170 }
 171
 172 const char* ImageView::GetClassName() const {
 173   return kViewClassName;
 174 }
 175
 176 void ImageView::SetHorizontalAlignment(Alignment ha) {
 177   if (ha != horiz_alignment_) {
 178     horiz_alignment_ = ha;
 179     SchedulePaint();
 180   }
 181 }
 182
 183 ImageView::Alignment ImageView::GetHorizontalAlignment() const {
 184   return horiz_alignment_;
 185 }
 186
 187 void ImageView::SetVerticalAlignment(Alignment va) {
 188   if (va != vert_alignment_) {
 189     vert_alignment_ = va;
 190     SchedulePaint();
 191   }
 192 }
 193
 194 ImageView::Alignment ImageView::GetVerticalAlignment() const {
 195   return vert_alignment_;
 196 }
 197
 198 void ImageView::SetTooltipText(const base::string16& tooltip) {
 199   tooltip_text_ = tooltip;
 200 }
 201
 202 base::string16 ImageView::GetTooltipText() const {
 203   return tooltip_text_;
 204 }
 205
 206 bool ImageView::GetTooltipText(const gfx::Point& p,
 207                                base::string16* tooltip) const {
 208   if (tooltip_text_.empty())
 209     return false;
 210
 211   *tooltip = GetTooltipText();
 212   return true;
 213 }
 214
 215 bool ImageView::CanProcessEventsWithinSubtree() const {
 216   return interactive_;
 217 }
 218
 219 void ImageView::OnPaintImage(gfx::Canvas* canvas) {
 220   last_paint_scale_ = canvas->image_scale();
 221   last_painted_bitmap_pixels_ = NULL;
 222
 223   if (image_.isNull())
 224     return;
 225
 226   gfx::Rect image_bounds(GetImageBounds());
 227   if (image_bounds.IsEmpty())
 228     return;
 229
 230   if (image_bounds.size() != gfx::Size(image_.width(), image_.height())) {
 231     // Resize case
 232     SkPaint paint;
 233     paint.setFilterQuality(kLow_SkFilterQuality);
 234     canvas->DrawImageInt(image_, 0, 0, image_.width(), image_.height(),
 235         image_bounds.x(), image_bounds.y(), image_bounds.width(),
 236         image_bounds.height(), true, paint);
 237   } else {
 238     canvas->DrawImageInt(image_, image_bounds.x(), image_bounds.y());
 239   }
 240   last_painted_bitmap_pixels_ = GetBitmapPixels(image_, last_paint_scale_);
 241 }
 242
 243 }  // namespace views