gecko/gfx/src/nsRenderingContext.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
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 *
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 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is thebes gfx
 *
 * The Initial Developer of the Original Code is
 * mozilla.org.
 * Portions created by the Initial Developer are Copyright (C) 2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Vladimir Vukicevic <vladimir@pobox.com>
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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#ifndef NSRENDERINGCONTEXT__H__
#define NSRENDERINGCONTEXT__H__

#include "nsAutoPtr.h"
#include "nsDeviceContext.h"
#include "nsFontMetrics.h"
#include "nsColor.h"
#include "nsCoord.h"
#include "gfxContext.h"

struct nsPoint;
class nsIntRegion;

typedef enum {
    nsLineStyle_kNone   = 0,
    nsLineStyle_kSolid  = 1,
    nsLineStyle_kDashed = 2,
    nsLineStyle_kDotted = 3
} nsLineStyle;

class nsRenderingContext
{
public:
    nsRenderingContext() : mP2A(0.) {}
    // ~nsRenderingContext() {}

    NS_INLINE_DECL_REFCOUNTING(nsRenderingContext)

    void Init(nsDeviceContext* aContext, gfxASurface* aThebesSurface);
    void Init(nsDeviceContext* aContext, gfxContext* aThebesContext);

    // These accessors will never return null.
    gfxContext *ThebesContext() { return mThebes; }
    nsDeviceContext *DeviceContext() { return mDeviceContext; }
    PRUint32 AppUnitsPerDevPixel() { return NSToIntRound(mP2A); }

    // Graphics state

    void PushState(void);
    void PopState(void);
    void IntersectClip(const nsRect& aRect);
    void SetClip(const nsIntRegion& aRegion);
    void SetLineStyle(nsLineStyle aLineStyle);
    void SetColor(nscolor aColor);
    void Translate(const nsPoint& aPt);
    void Scale(float aSx, float aSy);

    class AutoPushTranslation {
        nsRenderingContext* mCtx;
    public:
        AutoPushTranslation(nsRenderingContext* aCtx, const nsPoint& aPt)
            : mCtx(aCtx) {
            mCtx->PushState();
            mCtx->Translate(aPt);
        }
        ~AutoPushTranslation() {
            mCtx->PopState();
        }
    };

    // Shapes

    void DrawLine(const nsPoint& aStartPt, const nsPoint& aEndPt);
    void DrawLine(nscoord aX0, nscoord aY0, nscoord aX1, nscoord aY1);
    void DrawRect(const nsRect& aRect);
    void DrawRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
    void DrawEllipse(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);

    void FillRect(const nsRect& aRect);
    void FillRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
    void FillPolygon(const nsPoint aPoints[], PRInt32 aNumPoints);

    void FillEllipse(const nsRect& aRect);
    void FillEllipse(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);

    void InvertRect(const nsRect& aRect);

    // Text

    void SetFont(nsFontMetrics *aFontMetrics);
    nsFontMetrics *FontMetrics() { return mFontMetrics; } // may be null

    void SetTextRunRTL(bool aIsRTL);

    nscoord GetWidth(char aC);
    nscoord GetWidth(PRUnichar aC);
    nscoord GetWidth(const nsString& aString);
    nscoord GetWidth(const char* aString);
    nscoord GetWidth(const char* aString, PRUint32 aLength);
    nscoord GetWidth(const PRUnichar *aString, PRUint32 aLength);

    nsBoundingMetrics GetBoundingMetrics(const PRUnichar *aString,
                                         PRUint32 aLength);

    void DrawString(const nsString& aString, nscoord aX, nscoord aY);
    void DrawString(const char *aString, PRUint32 aLength,
                    nscoord aX, nscoord aY);
    void DrawString(const PRUnichar *aString, PRUint32 aLength,
                    nscoord aX, nscoord aY);

protected:
    PRInt32 GetMaxChunkLength();

    nsRefPtr<gfxContext> mThebes;
    nsRefPtr<nsDeviceContext> mDeviceContext;
    nsRefPtr<nsFontMetrics> mFontMetrics;

    double mP2A; // cached app units per device pixel value
};

#endif  // NSRENDERINGCONTEXT__H__