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      1 
      2 /*
      3  * Copyright 2011 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 #ifndef SkPDFDevice_DEFINED
     11 #define SkPDFDevice_DEFINED
     12 
     13 #include "SkCanvas.h"
     14 #include "SkDevice.h"
     15 #include "SkPaint.h"
     16 #include "SkPath.h"
     17 #include "SkRefCnt.h"
     18 #include "SkStream.h"
     19 #include "SkTScopedPtr.h"
     20 
     21 class SkPDFArray;
     22 class SkPDFDevice;
     23 class SkPDFDict;
     24 class SkPDFFont;
     25 class SkPDFFormXObject;
     26 class SkPDFGlyphSetMap;
     27 class SkPDFGraphicState;
     28 class SkPDFObject;
     29 class SkPDFShader;
     30 class SkPDFStream;
     31 
     32 // Private classes.
     33 struct ContentEntry;
     34 struct GraphicStateEntry;
     35 
     36 /** \class SkPDFDevice
     37 
     38     The drawing context for the PDF backend.
     39 */
     40 class SkPDFDevice : public SkDevice {
     41 public:
     42     /** Create a PDF drawing context with the given width and height.
     43      *  72 points/in means letter paper is 612x792.
     44      *  @param pageSize Page size in points.
     45      *  @param contentSize The content size of the page in points. This will be
     46      *         combined with the initial transform to determine the drawing area
     47      *         (as reported by the width and height methods). Anything outside
     48      *         of the drawing area will be clipped.
     49      *  @param initialTransform The initial transform to apply to the page.
     50      *         This may be useful to, for example, move the origin in and
     51      *         over a bit to account for a margin, scale the canvas,
     52      *         or apply a rotation.  Note1: the SkPDFDevice also applies
     53      *         a scale+translate transform to move the origin from the
     54      *         bottom left (PDF default) to the top left.  Note2: drawDevice
     55      *         (used by layer restore) draws the device after this initial
     56      *         transform is applied, so the PDF device does an
     57      *         inverse scale+translate to accommodate the one that SkPDFDevice
     58      *         always does.
     59      */
     60     // TODO(vandebo): The sizes should be SkSize and not SkISize.
     61     SK_API SkPDFDevice(const SkISize& pageSize, const SkISize& contentSize,
     62                        const SkMatrix& initialTransform);
     63     SK_API virtual ~SkPDFDevice();
     64 
     65     virtual uint32_t getDeviceCapabilities() SK_OVERRIDE;
     66 
     67     virtual void clear(SkColor color) SK_OVERRIDE;
     68 
     69     /** These are called inside the per-device-layer loop for each draw call.
     70      When these are called, we have already applied any saveLayer operations,
     71      and are handling any looping from the paint, and any effects from the
     72      DrawFilter.
     73      */
     74     virtual void drawPaint(const SkDraw&, const SkPaint& paint) SK_OVERRIDE;
     75     virtual void drawPoints(const SkDraw&, SkCanvas::PointMode mode,
     76                             size_t count, const SkPoint[],
     77                             const SkPaint& paint) SK_OVERRIDE;
     78     virtual void drawRect(const SkDraw&, const SkRect& r, const SkPaint& paint);
     79     virtual void drawPath(const SkDraw&, const SkPath& origpath,
     80                           const SkPaint& paint, const SkMatrix* prePathMatrix,
     81                           bool pathIsMutable) SK_OVERRIDE;
     82     virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
     83                             const SkIRect* srcRectOrNull,
     84                             const SkMatrix& matrix, const SkPaint&) SK_OVERRIDE;
     85     virtual void drawSprite(const SkDraw&, const SkBitmap& bitmap, int x, int y,
     86                             const SkPaint& paint) SK_OVERRIDE;
     87     virtual void drawText(const SkDraw&, const void* text, size_t len,
     88                           SkScalar x, SkScalar y, const SkPaint&) SK_OVERRIDE;
     89     virtual void drawPosText(const SkDraw&, const void* text, size_t len,
     90                              const SkScalar pos[], SkScalar constY,
     91                              int scalarsPerPos, const SkPaint&) SK_OVERRIDE;
     92     virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
     93                                 const SkPath& path, const SkMatrix* matrix,
     94                                 const SkPaint& paint) SK_OVERRIDE;
     95     virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode,
     96                               int vertexCount, const SkPoint verts[],
     97                               const SkPoint texs[], const SkColor colors[],
     98                               SkXfermode* xmode, const uint16_t indices[],
     99                               int indexCount, const SkPaint& paint) SK_OVERRIDE;
    100     virtual void drawDevice(const SkDraw&, SkDevice*, int x, int y,
    101                             const SkPaint&) SK_OVERRIDE;
    102 
    103     enum DrawingArea {
    104         kContent_DrawingArea,  // Drawing area for the page content.
    105         kMargin_DrawingArea,   // Drawing area for the margin content.
    106     };
    107 
    108     /** Sets the drawing area for the device. Subsequent draw calls are directed
    109      *  to the specific drawing area (margin or content). The default drawing
    110      *  area is the content drawing area.
    111      *
    112      *  Currently if margin content is drawn and then a complex (for PDF) xfer
    113      *  mode is used, like SrcIn, Clear, etc, the margin content will get
    114      *  clipped. A simple way to avoid the bug is to always draw the margin
    115      *  content last.
    116      */
    117     SK_API void setDrawingArea(DrawingArea drawingArea);
    118 
    119     // PDF specific methods.
    120 
    121     /** Returns the resource dictionary for this device.
    122      */
    123     SK_API SkPDFDict* getResourceDict();
    124 
    125     /** Get the list of resources (PDF objects) used on this page.
    126      *  @param resourceList A list to append the resources to.
    127      */
    128     SK_API void getResources(SkTDArray<SkPDFObject*>* resourceList) const;
    129 
    130     /** Get the fonts used on this device.
    131      */
    132     SK_API const SkTDArray<SkPDFFont*>& getFontResources() const;
    133 
    134     /** Returns the media box for this device.
    135      */
    136     SK_API SkRefPtr<SkPDFArray> getMediaBox() const;
    137 
    138     /** Returns a SkStream with the page contents.  The caller is responsible
    139         for a reference to the returned value.
    140         DEPRECATED: use copyContentToData()
    141      */
    142     SK_API SkStream* content() const;
    143 
    144     /** Returns a SkStream with the page contents.  The caller is responsible
    145      *  for calling data->unref() when it is finished.
    146      */
    147     SK_API SkData* copyContentToData() const;
    148 
    149     SK_API const SkMatrix& initialTransform() const {
    150         return fInitialTransform;
    151     }
    152 
    153     /** Returns a SkPDFGlyphSetMap which represents glyph usage of every font
    154      *  that shows on this device.
    155      */
    156     const SkPDFGlyphSetMap& getFontGlyphUsage() const {
    157         return *(fFontGlyphUsage.get());
    158     }
    159 
    160 protected:
    161     virtual bool onReadPixels(const SkBitmap& bitmap, int x, int y,
    162                               SkCanvas::Config8888) SK_OVERRIDE;
    163 
    164     virtual bool allowImageFilter(SkImageFilter*) SK_OVERRIDE;
    165 
    166 private:
    167     // TODO(vandebo): push most of SkPDFDevice's state into a core object in
    168     // order to get the right access levels without using friend.
    169     friend class ScopedContentEntry;
    170 
    171     SkISize fPageSize;
    172     SkISize fContentSize;
    173     SkMatrix fInitialTransform;
    174     SkClipStack fExistingClipStack;
    175     SkRegion fExistingClipRegion;
    176     SkRefPtr<SkPDFDict> fResourceDict;
    177 
    178     SkTDArray<SkPDFGraphicState*> fGraphicStateResources;
    179     SkTDArray<SkPDFObject*> fXObjectResources;
    180     SkTDArray<SkPDFFont*> fFontResources;
    181     SkTDArray<SkPDFObject*> fShaderResources;
    182 
    183     SkTScopedPtr<ContentEntry> fContentEntries;
    184     ContentEntry* fLastContentEntry;
    185     SkTScopedPtr<ContentEntry> fMarginContentEntries;
    186     ContentEntry* fLastMarginContentEntry;
    187     DrawingArea fDrawingArea;
    188 
    189     // Accessor and setter functions based on the current DrawingArea.
    190     SkTScopedPtr<ContentEntry>* getContentEntries();
    191     ContentEntry* getLastContentEntry();
    192     void setLastContentEntry(ContentEntry* contentEntry);
    193 
    194     // Glyph ids used for each font on this device.
    195     SkTScopedPtr<SkPDFGlyphSetMap> fFontGlyphUsage;
    196 
    197     SkPDFDevice(const SkISize& layerSize, const SkClipStack& existingClipStack,
    198                 const SkRegion& existingClipRegion);
    199 
    200     // override from SkDevice
    201     virtual SkDevice* onCreateCompatibleDevice(SkBitmap::Config config,
    202                                                int width, int height,
    203                                                bool isOpaque,
    204                                                Usage usage) SK_OVERRIDE;
    205 
    206     void init();
    207     void cleanUp(bool clearFontUsage);
    208     void createFormXObjectFromDevice(SkRefPtr<SkPDFFormXObject>* xobject);
    209 
    210     // Clear the passed clip from all existing content entries.
    211     void clearClipFromContent(const SkClipStack* clipStack,
    212                               const SkRegion& clipRegion);
    213     void drawFormXObjectWithClip(SkPDFFormXObject* form,
    214                                  const SkClipStack* clipStack,
    215                                  const SkRegion& clipRegion,
    216                                  bool invertClip);
    217 
    218     // If the paint or clip is such that we shouldn't draw anything, this
    219     // returns NULL and does not create a content entry.
    220     // setUpContentEntry and finishContentEntry can be used directly, but
    221     // the preferred method is to use the ScopedContentEntry helper class.
    222     ContentEntry* setUpContentEntry(const SkClipStack* clipStack,
    223                                     const SkRegion& clipRegion,
    224                                     const SkMatrix& matrix,
    225                                     const SkPaint& paint,
    226                                     bool hasText,
    227                                     SkRefPtr<SkPDFFormXObject>* dst);
    228     void finishContentEntry(SkXfermode::Mode xfermode,
    229                             SkPDFFormXObject* dst);
    230     bool isContentEmpty();
    231 
    232     void populateGraphicStateEntryFromPaint(const SkMatrix& matrix,
    233                                             const SkClipStack& clipStack,
    234                                             const SkRegion& clipRegion,
    235                                             const SkPaint& paint,
    236                                             bool hasText,
    237                                             GraphicStateEntry* entry);
    238     int addGraphicStateResource(SkPDFGraphicState* gs);
    239 
    240     void updateFont(const SkPaint& paint, uint16_t glyphID,
    241                     ContentEntry* contentEntry);
    242     int getFontResourceIndex(SkTypeface* typeface, uint16_t glyphID);
    243 
    244     void internalDrawPaint(const SkPaint& paint, ContentEntry* contentEntry);
    245     void internalDrawBitmap(const SkMatrix& matrix,
    246                             const SkClipStack* clipStack,
    247                             const SkRegion& clipRegion,
    248                             const SkBitmap& bitmap,
    249                             const SkIRect* srcRect,
    250                             const SkPaint& paint);
    251 
    252     /** Helper method for copyContentToData. It is responsible for copying the
    253      *  list of content entries |entry| to |data|.
    254      */
    255     void copyContentEntriesToData(ContentEntry* entry, SkWStream* data) const;
    256 
    257     // Disable the default copy and assign implementation.
    258     SkPDFDevice(const SkPDFDevice&);
    259     void operator=(const SkPDFDevice&);
    260 };
    261 
    262 #endif
    263