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