Move platform/graphics/chromium/* to platform/graphics/

Source/core/platform/graphics/chromium/TransparencyWin.h

-/*
- * Copyright (C) 2009 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef TransparencyWin_h
-#define TransparencyWin_h
-
-#include <windows.h>
-
-#include "core/platform/graphics/ImageBuffer.h"
-#include "platform/transforms/AffineTransform.h"
-
-#include "wtf/Noncopyable.h"
-#include "wtf/OwnPtr.h"
-
-class SkBitmap;
-class SkCanvas;
-
-namespace WebCore {
-
-class GraphicsContext;
-class TransparencyWin_NoLayer_Test;
-class TransparencyWin_WhiteLayer_Test;
-class TransparencyWin_TextComposite_Test;
-class TransparencyWin_OpaqueCompositeLayer_Test;
-
-// Helper class that abstracts away drawing ClearType text and Windows form
-// controls either to the original context directly, or to an offscreen context
-// that is composited later manually. This is to get around Windows' inability
-// to handle the alpha channel, semitransparent text, and transformed form
-// controls.
-class TransparencyWin {
-    WTF_MAKE_NONCOPYABLE(TransparencyWin);
-public:
-    enum LayerMode {
-        // No extra layer is created. Drawing will happen to the source.
-        // Valid only with KeepTransform and ScaleTransform. The region being
-        // drawn onto must be opaque, since the modified region will be forced
-        // to opaque when drawing is complete.
-        NoLayer,
-
-        // Makes a temporary layer consisting of the composited layers below
-        // it. This result must be opaque. When complete, the result will be
-        // compared to the original, and the difference will be added to a thee
-        // destination layer.
-        //
-        // This mode only works if the lower layers are opque (normally the
-        // case for a web page) and layers are only drawn in the stack order,
-        // meaning you can never draw underneath a layer.
-        //
-        // This doesn't technically produce the correct answer in all cases. If
-        // you have an opaque base, a transparency layer, than a semitransparent
-        // drawing on top, the result will actually be blended in twice. But
-        // this isn't a very important case. This mode is used for form
-        // controls which are always opaque except for occationally some
-        // antialiasing. It means form control antialiasing will be too light in
-        // some cases, but only if you have extra layers.
-        OpaqueCompositeLayer,
-
-        // Allows semitransparent text to be drawn on any background (even if it
-        // is itself semitransparent), but disables ClearType.
-        //
-        // It makes a trmporary layer filled with white. This is composited with
-        // the lower layer with a custom color applied to produce the result.
-        // The caller must draw the text in black, and set the desired final
-        // text color by calling setTextCompositeColor().
-        //
-        // Only valid with KeepTransform, which is the only mode where drawing
-        // text in this fashion makes sense.
-        TextComposite,
-
-        // Makes a temporary layer filled with white. When complete, the layer
-        // will be forced to be opqaue (since Windows may have messed up the
-        // alpha channel) and composited down. Any areas not drawn into will
-        // remain white.
-        //
-        // This is the mode of last resort. If the opacity of the final image
-        // is unknown and we can't do the text trick (since we know its color),
-        // then we have to live with potential white halos. This is used for
-        // form control drawing, for example.
-        WhiteLayer,
-    };
-
-    enum TransformMode {
-        // There are no changes to the transform. Use this when drawing
-        // horizontal text. The current transform must not have rotation.
-        KeepTransform,
-
-        // Drawing happens in an Untransformed space, and then that bitmap is
-        // transformed according to the current context when it is copied down.
-        // Requires that a layer be created (layer mode is not NoLayer).
-        Untransform,
-
-        // When the current transform only has a scaling factor applied and
-        // you're drawing form elements, use this parameter. This will unscale
-        // the coordinate space, so the OS will just draw the form controls
-        // larger or smaller depending on the destination size.
-        ScaleTransform,
-    };
-
-    // You MUST call init() below.
-    // |region| is expressed relative to the current transformation.
-    TransparencyWin();
-    ~TransparencyWin();
-
-    // Initializes the members if you use the 0-argument constructor. Don't call
-    // this if you use the multiple-argument constructor.
-    void init(GraphicsContext* dest,
-              LayerMode layerMode,
-              TransformMode transformMode,
-              const IntRect& region);
-
-    // Combines the source and destination bitmaps using the given mode.
-    // Calling this function before the destructor runs is mandatory in most
-    // cases, and harmless otherwise.  The mandatory cases are:
-    //       (m_layerMode != NoLayer) || (m_transformMode == ScaleTransform)
-    void composite();
-
-    // Returns the context for drawing into, which may be the destination
-    // context, or a temporary one.
-    GraphicsContext* context() const { return m_drawContext; }
-
-    // When the mode is TextComposite, this sets the color that the text will
-    // get. See the enum above for more.
-    void setTextCompositeColor(Color color);
-
-    // Returns the input bounds translated into the destination space. This is
-    // not necessary for KeepTransform since the rectangle will be unchanged.
-    const IntRect& drawRect() { return m_drawRect; }
-
-private:
-    friend TransparencyWin_NoLayer_Test;
-    friend TransparencyWin_WhiteLayer_Test;
-    friend TransparencyWin_TextComposite_Test;
-    friend TransparencyWin_OpaqueCompositeLayer_Test;
-
-    class OwnedBuffers;
-
-    void computeLayerSize();
-
-    // Sets up a new layer, if any. setupLayer() will call the appopriate layer-
-    // specific helper. Must be called after computeLayerSize();
-    void setupLayer();
-    void setupLayerForNoLayer();
-    void setupLayerForOpaqueCompositeLayer();
-    void setupLayerForTextComposite();
-    void setupLayerForWhiteLayer();
-
-    // Sets up the transformation on the newly created layer. setupTransform()
-    // will call the appropriate transform-specific helper. Must be called after
-    // setupLayer().
-    void setupTransform(const IntRect& region);
-    void setupTransformForKeepTransform(const IntRect& region);
-    void setupTransformForUntransform();
-    void setupTransformForScaleTransform();
-
-    void initializeNewContext();
-
-    void compositeOpaqueComposite();
-    void compositeTextComposite();
-
-    // Fixes the alpha channel to make the region inside m_transformedRect
-    // opaque.
-    void makeLayerOpaque();
-
-    // The context our drawing will eventually end up in.
-    GraphicsContext* m_destContext;
-
-    // The original transform from the destination context.
-    AffineTransform m_orgTransform;
-
-    LayerMode m_layerMode;
-    TransformMode m_transformMode;
-
-    // The rectangle we're drawing in the destination's coordinate space
-    IntRect m_sourceRect;
-
-    // The source rectangle transformed into pixels in the final image. For
-    // Untransform this has no meaning, since the destination might not be a
-    // rectangle.
-    IntRect m_transformedSourceRect;
-
-    // The size of the layer we created. If there's no layer, this is the size
-    // of the region we're using in the source.
-    IntSize m_layerSize;
-
-    // The rectangle we're drawing to in the draw context's coordinate space.
-    // This will be the same as the source rectangle except for ScaleTransform
-    // where we create a new virtual coordinate space for the layer.
-    IntRect m_drawRect;
-
-    // Points to the graphics context to draw text to, which will either be
-    // the original context or the copy, depending on our mode.
-    GraphicsContext* m_drawContext;
-
-    // This flag is set when we call save() on the draw context during
-    // initialization. It allows us to avoid doing an extra save()/restore()
-    // when one is unnecessary.
-    bool m_savedOnDrawContext;
-
-    // Used only when m_mode = TextComposite, this is the color that the text
-    // will end up being once we figure out the transparency.
-    Color m_textCompositeColor;
-
-    // Layer we're drawing to.
-    ImageBuffer* m_layerBuffer;
-
-    // When the layer type is OpaqueCompositeLayer, this will contain a copy
-    // of the original contents of the m_layerBuffer before Windows drew on it.
-    // It allows us to re-create what Windows did to the layer. It is an
-    // SkBitmap instead of an ImageBuffer because an SkBitmap is lighter-weight
-    // (ImageBuffers are also GDI surfaces, which we don't need here).
-    SkBitmap* m_referenceBitmap;
-
-    // If the given size of bitmap can be cached, they will be stored here. Both
-    // the bitmap and the reference are guaranteed to be allocated if this
-    // member is non-null.
-    static OwnedBuffers* m_cachedBuffers;
-
-    // If a buffer was too big to be cached, it will be created temporarily, and
-    // this member tracks its scope to make sure it gets deleted. Always use
-    // m_layerBuffer, which will either point to this object, or the statically
-    // cached one. Don't access directly.
-    OwnPtr<OwnedBuffers> m_ownedBuffers;
-
-    // Sometimes we're asked to create layers that have negative dimensions.
-    // This API is not designed to fail to initialize, so we hide the fact
-    // that they are illegal and can't be rendered (failing silently, drawing
-    // nothing).
-    bool m_validLayer;
-};
-
-} // namespace WebCore
-
-#endif // TransaprencyWin_h