skia2/include/pdf/SkPDFDevice.h

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef SkPDFDevice_DEFINED
#define SkPDFDevice_DEFINED

#include "SkRefCnt.h"
#include "SkDevice.h"
#include "SkString.h"

class SkPDFArray;
class SkPDFDevice;
class SkPDFDict;
class SkPDFGraphicState;
class SkPDFObject;
class SkPDFStream;

class SkPDFDeviceFactory : public SkDeviceFactory {
    virtual SkDevice* newDevice(SkBitmap::Config config, int width, int height,
                                bool isOpaque, bool isForLayer);
    virtual uint32_t getDeviceCapabilities() { return 0; }
};

/** \class SkPDFDevice

    The drawing context for the PDF backend.
*/
class SkPDFDevice : public SkDevice {
public:
    /** Create a PDF drawing context with the given width and height.
     *  72 points/in means letter paper is 612x792.
     *  @param width  Page width in points.
     *  @param height Page height in points.
     */
    SkPDFDevice(int width, int height);
    virtual ~SkPDFDevice();

    virtual SkDeviceFactory* getDeviceFactory() {
        return SkNEW(SkPDFDeviceFactory);
    }

    virtual int width() const { return fWidth; };

    virtual int height() const { return fHeight; };

    /** Called with the correct matrix and clip before this device is drawn
        to using those settings. If your subclass overrides this, be sure to
        call through to the base class as well.
    */
    virtual void setMatrixClip(const SkMatrix&, const SkRegion&);

    /** These are called inside the per-device-layer loop for each draw call.
     When these are called, we have already applied any saveLayer operations,
     and are handling any looping from the paint, and any effects from the
     DrawFilter.
     */
    virtual void drawPaint(const SkDraw&, const SkPaint& paint);
    virtual void drawPoints(const SkDraw&, SkCanvas::PointMode mode,
                            size_t count, const SkPoint[],
                            const SkPaint& paint);
    virtual void drawRect(const SkDraw&, const SkRect& r, const SkPaint& paint);
    virtual void drawPath(const SkDraw&, const SkPath& path,
                          const SkPaint& paint);
    virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
                            const SkMatrix& matrix, const SkPaint& paint);
    virtual void drawSprite(const SkDraw&, const SkBitmap& bitmap, int x, int y,
                            const SkPaint& paint);
    virtual void drawText(const SkDraw&, const void* text, size_t len,
                          SkScalar x, SkScalar y, const SkPaint& paint);
    virtual void drawPosText(const SkDraw&, const void* text, size_t len,
                             const SkScalar pos[], SkScalar constY,
                             int scalarsPerPos, const SkPaint& paint);
    virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
                                const SkPath& path, const SkMatrix* matrix,
                                const SkPaint& paint);
    virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode,
                              int vertexCount, const SkPoint verts[],
                              const SkPoint texs[], const SkColor colors[],
                              SkXfermode* xmode, const uint16_t indices[],
                              int indexCount, const SkPaint& paint);
    virtual void drawDevice(const SkDraw&, SkDevice*, int x, int y,
                            const SkPaint&);

    // PDF specific methods.

    /** Returns a reference to the resource dictionary for this device.
     */
    const SkRefPtr<SkPDFDict>& getResourceDict();

    /** Get the list of resouces (PDF objects) used on this page
     *  @param resouceList A list to append the resouces to.
     */
    void getResouces(SkTDArray<SkPDFObject*>* resouceList);

    /** Returns the media box for this device.
     */
    SkRefPtr<SkPDFArray> getMediaBox();

    /** Returns a string with the page contents.
     */
    SkString content();

private:
    int fWidth;
    int fHeight;
    SkRefPtr<SkPDFDict> fResourceDict;

    SkRefPtr<SkPDFGraphicState> fCurrentGraphicState;
    SkColor fCurrentColor;
    SkScalar fCurrentTextScaleX;
    SkTDArray<SkPDFGraphicState*> fGraphicStateResources;
    SkTDArray<SkPDFObject*> fXObjectResources;

    SkString fContent;

    // The last requested transforms from SkCanvas (setMatrixClip)
    SkMatrix fCurTransform;

    // The transform currently in effect in the PDF content stream.
    SkMatrix fActiveTransform;

    void updateGSFromPaint(const SkPaint& newPaint, SkString* textStaetUpdate);

    void moveTo(SkScalar x, SkScalar y);
    void appendLine(SkScalar x, SkScalar y);
    void appendCubic(SkScalar ctl1X, SkScalar ctl1Y,
                     SkScalar ctl2X, SkScalar ctl2Y,
                     SkScalar dstX, SkScalar dstY);
    void appendRectangle(SkScalar x, SkScalar y, SkScalar w, SkScalar h);
    void closePath();
    void strokePath();
    void internalDrawBitmap(const SkMatrix& matrix, const SkBitmap& bitmap,
                            const SkPaint& paint);

    void setTransform(const SkMatrix& matrix);
    void setNoTransform();
    void applyTempTransform(const SkMatrix& matrix);
    void removeTempTransform();
    void applyTransform(const SkMatrix& matrix);
};

#endif