NOT FOR SUBMIT - Windows Views HiDPI

ui/gfx/canvas_paint_win.h

Index: ui/gfx/canvas_paint_win.h
diff --git a/ui/gfx/canvas_paint_win.h b/ui/gfx/canvas_paint_win.h
index 1316b9616bd7f0e719c4e7a0c14d62ea81ed7100..8523cc031ebaedfd6a55637b7adcff062949796a 100644
--- a/ui/gfx/canvas_paint_win.h
+++ b/ui/gfx/canvas_paint_win.h
@@ -1,135 +1,138 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.

[kevers, 2013/04/19 20:31:42]

CRLF issue?

-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_GFX_CANVAS_PAINT_WIN_H_
-#define UI_GFX_CANVAS_PAINT_WIN_H_
-
-#include "skia/ext/platform_canvas.h"
-#include "ui/gfx/canvas.h"
-#include "ui/gfx/canvas_paint.h"
-#include "ui/gfx/size.h"
-
-namespace gfx {
-
-// A class designed to help with WM_PAINT operations on Windows. It will
-// do BeginPaint/EndPaint on init/destruction, and will create the bitmap and
-// canvas with the correct size and transform for the dirty rect. The bitmap
-// will be automatically painted to the screen on destruction.
-//
-// You MUST call isEmpty before painting to determine if anything needs
-// painting. Sometimes the dirty rect can actually be empty, and this makes
-// the bitmap functions we call unhappy. The caller should not paint in this
-// case.
-//
-// Therefore, all you need to do is:
-//   case WM_PAINT: {
-//     gfx::PlatformCanvasPaint canvas(hwnd);
-//     if (!canvas.isEmpty()) {
-//       ... paint to the canvas ...
-//     }
-//     return 0;
-//   }
-// Note: The created context is always inialized to (0, 0, 0, 0).
-class UI_EXPORT CanvasSkiaPaint : public Canvas {
- public:
-  // This constructor assumes the canvas is opaque.
-  explicit CanvasSkiaPaint(HWND hwnd) : hwnd_(hwnd), paint_dc_(NULL),
-    for_paint_(true) {
-    memset(&ps_, 0, sizeof(ps_));
-    initPaint(true);
-  }
-
-  CanvasSkiaPaint(HWND hwnd, bool opaque) : hwnd_(hwnd), paint_dc_(NULL),
-      for_paint_(true) {
-    memset(&ps_, 0, sizeof(ps_));
-    initPaint(opaque);
-  }
-
-  // Creates a CanvasSkiaPaint for the specified region that paints to the
-  // specified dc. This does NOT do BeginPaint/EndPaint.
-  CanvasSkiaPaint(HDC dc, bool opaque, int x, int y, int w, int h)
-      : hwnd_(NULL),
-        paint_dc_(dc),
-        for_paint_(false) {
-    memset(&ps_, 0, sizeof(ps_));
-    ps_.rcPaint.left = x;
-    ps_.rcPaint.right = x + w;
-    ps_.rcPaint.top = y;
-    ps_.rcPaint.bottom = y + h;
-    init(opaque);
-  }
-
-  virtual ~CanvasSkiaPaint() {
-    if (!isEmpty()) {
-      skia::PlatformCanvas* canvas = platform_canvas();
-      canvas->restoreToCount(1);
-      // Commit the drawing to the screen
-      skia::DrawToNativeContext(canvas, paint_dc_, ps_.rcPaint.left,
-                                ps_.rcPaint.top, NULL);
-    }
-    if (for_paint_)
-      EndPaint(hwnd_, &ps_);
-  }
-
-  // Returns true if the invalid region is empty. The caller should call this
-  // function to determine if anything needs painting.
-  bool isEmpty() const {
-    return ps_.rcPaint.right - ps_.rcPaint.left == 0 ||
-           ps_.rcPaint.bottom - ps_.rcPaint.top == 0;
-  }
-
-  // Use to access the Windows painting parameters, especially useful for
-  // getting the bounding rect for painting: paintstruct().rcPaint
-  const PAINTSTRUCT& paintStruct() const {
-    return ps_;
-  }
-
-  // Returns the DC that will be painted to
-  HDC paintDC() const {
-    return paint_dc_;
-  }
-
- protected:
-  HWND hwnd_;
-  HDC paint_dc_;
-  PAINTSTRUCT ps_;
-
- private:
-  void initPaint(bool opaque) {
-    paint_dc_ = BeginPaint(hwnd_, &ps_);
-
-    init(opaque);
-  }
-
-  void init(bool opaque) {
-    // FIXME(brettw) for ClearType, we probably want to expand the bounds of
-    // painting by one pixel so that the boundaries will be correct (ClearType
-    // text can depend on the adjacent pixel). Then we would paint just the
-    // inset pixels to the screen.
-    const int width = ps_.rcPaint.right - ps_.rcPaint.left;
-    const int height = ps_.rcPaint.bottom - ps_.rcPaint.top;
-
-    RecreateBackingCanvas(gfx::Size(width, height), ui::SCALE_FACTOR_100P,
-                          opaque);
-    skia::PlatformCanvas* canvas = platform_canvas();
-
-    canvas->clear(SkColorSetARGB(0, 0, 0, 0));
-
-    // This will bring the canvas into the screen coordinate system for the
-    // dirty rect
-    canvas->translate(SkIntToScalar(-ps_.rcPaint.left),
-                      SkIntToScalar(-ps_.rcPaint.top));
-  }
-
-  // If true, this canvas was created for a BeginPaint.
-  const bool for_paint_;
-
-  // Disallow copy and assign.
-  CanvasSkiaPaint(const CanvasSkiaPaint&);
-  CanvasSkiaPaint& operator=(const CanvasSkiaPaint&);
-};
-
-}  // namespace gfx
-
-#endif  // UI_GFX_CANVAS_PAINT_WIN_H_
+// Copyright (c) 2011 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.
+
+#ifndef UI_GFX_CANVAS_PAINT_WIN_H_
+#define UI_GFX_CANVAS_PAINT_WIN_H_
+
+#include "skia/ext/platform_canvas.h"
+#include "ui/base/win/dpi.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/canvas_paint.h"
+#include "ui/gfx/size.h"
+
+namespace gfx {
+
+// A class designed to help with WM_PAINT operations on Windows. It will
+// do BeginPaint/EndPaint on init/destruction, and will create the bitmap and
+// canvas with the correct size and transform for the dirty rect. The bitmap
+// will be automatically painted to the screen on destruction.
+//
+// You MUST call isEmpty before painting to determine if anything needs
+// painting. Sometimes the dirty rect can actually be empty, and this makes
+// the bitmap functions we call unhappy. The caller should not paint in this
+// case.
+//
+// Therefore, all you need to do is:
+//   case WM_PAINT: {
+//     gfx::PlatformCanvasPaint canvas(hwnd);
+//     if (!canvas.isEmpty()) {
+//       ... paint to the canvas ...
+//     }
+//     return 0;
+//   }
+// Note: The created context is always inialized to (0, 0, 0, 0).
+class UI_EXPORT CanvasSkiaPaint : public Canvas {
+ public:
+  // This constructor assumes the canvas is opaque.
+  explicit CanvasSkiaPaint(HWND hwnd) : hwnd_(hwnd), paint_dc_(NULL),
+    for_paint_(true) {
+    memset(&ps_, 0, sizeof(ps_));
+    initPaint(true);
+  }
+
+  CanvasSkiaPaint(HWND hwnd, bool opaque) : hwnd_(hwnd), paint_dc_(NULL),
+      for_paint_(true) {
+    memset(&ps_, 0, sizeof(ps_));
+    initPaint(opaque);
+  }
+
+  // Creates a CanvasSkiaPaint for the specified region that paints to the
+  // specified dc. This does NOT do BeginPaint/EndPaint.
+  CanvasSkiaPaint(HDC dc, bool opaque, int x, int y, int w, int h)
+      : hwnd_(NULL),
+        paint_dc_(dc),
+        for_paint_(false) {
+    memset(&ps_, 0, sizeof(ps_));
+    ps_.rcPaint.left = x;
+    ps_.rcPaint.right = x + w;
+    ps_.rcPaint.top = y;
+    ps_.rcPaint.bottom = y + h;
+    init(opaque);
+  }
+
+  virtual ~CanvasSkiaPaint() {
+    if (!isEmpty()) {
+      skia::PlatformCanvas* canvas = platform_canvas();
+      canvas->restoreToCount(1);
+      // Commit the drawing to the screen
+      skia::DrawToNativeContext(canvas, paint_dc_, ps_.rcPaint.left,
+                                ps_.rcPaint.top, NULL);
+    }
+    if (for_paint_)
+      EndPaint(hwnd_, &ps_);
+  }
+
+  // Returns true if the invalid region is empty. The caller should call this
+  // function to determine if anything needs painting.
+  bool isEmpty() const {
+    return ps_.rcPaint.right - ps_.rcPaint.left == 0 ||
+           ps_.rcPaint.bottom - ps_.rcPaint.top == 0;
+  }
+
+  // Use to access the Windows painting parameters, especially useful for
+  // getting the bounding rect for painting: paintstruct().rcPaint
+  const PAINTSTRUCT& paintStruct() const {
+    return ps_;
+  }
+
+  // Returns the DC that will be painted to
+  HDC paintDC() const {
+    return paint_dc_;
+  }
+
+ protected:
+  HWND hwnd_;
+  HDC paint_dc_;
+  PAINTSTRUCT ps_;
+
+ private:
+  void initPaint(bool opaque) {
+    paint_dc_ = BeginPaint(hwnd_, &ps_);
+
+    init(opaque);
+  }
+
+  void init(bool opaque) {
+    // FIXME(brettw) for ClearType, we probably want to expand the bounds of
+    // painting by one pixel so that the boundaries will be correct (ClearType
+    // text can depend on the adjacent pixel). Then we would paint just the
+    // inset pixels to the screen.
+    const int width = ps_.rcPaint.right - ps_.rcPaint.left;
+    const int height = ps_.rcPaint.bottom - ps_.rcPaint.top;
+
+    RecreateBackingCanvas(gfx::Size(width, height),
+        ui::GetScaleFactorFromScale(ui::win::GetDeviceScaleFactor()),
+        opaque);
+    skia::PlatformCanvas* canvas = platform_canvas();
+
+    canvas->clear(SkColorSetARGB(0, 0, 0, 0));
+
+    // This will bring the canvas into the screen coordinate system for the
+    // dirty rect
+    canvas->translate(
+        SkScalarRoundToInt(-ps_.rcPaint.left/ui::win::GetDeviceScaleFactor()),
+        SkScalarRoundToInt(-ps_.rcPaint.top/ui::win::GetDeviceScaleFactor()));
+  }
+
+  // If true, this canvas was created for a BeginPaint.
+  const bool for_paint_;
+
+  // Disallow copy and assign.
+  CanvasSkiaPaint(const CanvasSkiaPaint&);
+  CanvasSkiaPaint& operator=(const CanvasSkiaPaint&);
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_CANVAS_PAINT_WIN_H_