/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* ***** BEGIN LICENSE BLOCK ***** * 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 * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is mozilla.org code. * * The Initial Developer of the Original Code is * Netscape Communications Corporation. * Portions created by the Initial Developer are Copyright (C) 1998 * the Initial Developer. All Rights Reserved. * * Contributor(s): * * Alternatively, the contents of this file may be used under the terms of * either of 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"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ /* utility functions for drawing borders and backgrounds */ #ifndef nsCSSRendering_h___ #define nsCSSRendering_h___ #include "nsIRenderingContext.h" #include "nsStyleConsts.h" #include "gfxBlur.h" #include "gfxContext.h" #include "gfxImageSurface.h" struct nsPoint; class nsStyleContext; class nsPresContext; struct nsCSSRendering { /** * Initialize any static variables used by nsCSSRendering. */ static nsresult Init(); /** * Clean up any static variables used by nsCSSRendering. */ static void Shutdown(); static void PaintBoxShadowInner(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aFrameArea, const nsRect& aDirtyRect); static void PaintBoxShadowOuter(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aFrameArea, const nsRect& aDirtyRect); static void ComputePixelRadii(const nscoord *aAppUnitsRadii, nscoord aAppUnitsPerPixel, gfxCornerSizes *oBorderRadii); /** * Render the border for an element using css rendering rules * for borders. aSkipSides is a bitmask of the sides to skip * when rendering. If 0 then no sides are skipped. */ static void PaintBorder(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aDirtyRect, const nsRect& aBorderArea, nsStyleContext* aStyleContext, PRIntn aSkipSides = 0); /** * Like PaintBorder, but taking an nsStyleBorder argument instead of * getting it from aStyleContext. */ static void PaintBorderWithStyleBorder(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aDirtyRect, const nsRect& aBorderArea, const nsStyleBorder& aBorderStyle, nsStyleContext* aStyleContext, PRIntn aSkipSides = 0); /** * Render the outline for an element using css rendering rules * for borders. aSkipSides is a bitmask of the sides to skip * when rendering. If 0 then no sides are skipped. */ static void PaintOutline(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aDirtyRect, const nsRect& aBorderArea, nsStyleContext* aStyleContext); /** * Render keyboard focus on an element. * |aFocusRect| is the outer rectangle of the focused element. * Uses a fixed style equivalent to "1px dotted |aColor|". * Not used for controls, because the native theme may differ. */ static void PaintFocus(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, const nsRect& aFocusRect, nscolor aColor); /** * Render a gradient for an element. */ static void PaintGradient(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsStyleGradient* aGradient, const nsRect& aDirtyRect, const nsRect& aOneCellArea, const nsRect& aFillArea); /** * Find the frame whose background style should be used to draw the * canvas background. aForFrame must be the frame for the root element * whose background style should be used. This function will return * aForFrame unless the background should be propagated, in * which case we return the frame associated with the 's background. */ static nsIFrame* FindBackgroundStyleFrame(nsIFrame* aForFrame); /** * @return PR_TRUE if |aFrame| is a canvas frame, in the CSS sense. */ static PRBool IsCanvasFrame(nsIFrame* aFrame); /** * Fill in an aBackgroundSC to be used to paint the background * for an element. This applies the rules for propagating * backgrounds between BODY, the root element, and the canvas. * @return PR_TRUE if there is some meaningful background. */ static PRBool FindBackground(nsPresContext* aPresContext, nsIFrame* aForFrame, nsStyleContext** aBackgroundSC); /** * As FindBackground, but the passed-in frame is known to be a root frame * (returned from nsCSSFrameConstructor::GetRootElementStyleFrame()) * and there is always some meaningful background returned. */ static nsStyleContext* FindRootFrameBackground(nsIFrame* aForFrame); /** * Returns background style information for the canvas. * * @param aForFrame * the frame used to represent the canvas, in the CSS sense (i.e. * nsCSSRendering::IsCanvasFrame(aForFrame) must be true) * @param aRootElementFrame * the frame representing the root element of the document * @param aBackground * contains background style information for the canvas on return */ static nsStyleContext* FindCanvasBackground(nsIFrame* aForFrame, nsIFrame* aRootElementFrame) { NS_ABORT_IF_FALSE(IsCanvasFrame(aForFrame), "not a canvas frame"); if (aRootElementFrame) return FindRootFrameBackground(aRootElementFrame); // This should always give transparent, so we'll fill it in with the // default color if needed. This seems to happen a bit while a page is // being loaded. return aForFrame->GetStyleContext(); } /** * Find a frame which draws a non-transparent background, * for various table-related and HR-related backwards-compatibility hacks. * This function will also stop if it finds themed frame which might draw * background. * * Be very hesitant if you're considering calling this function -- it's * usually not what you want. */ static nsIFrame* FindNonTransparentBackgroundFrame(nsIFrame* aFrame, PRBool aStartAtParent = PR_FALSE); /** * Determine the background color to draw taking into account print settings. */ static nscolor DetermineBackgroundColor(nsPresContext* aPresContext, nsStyleContext* aStyleContext, nsIFrame* aFrame); /** * Render the background for an element using css rendering rules * for backgrounds. */ enum { /** * When this flag is passed, the element's nsDisplayBorder will be * painted immediately on top of this background. */ PAINTBG_WILL_PAINT_BORDER = 0x01, /** * When this flag is passed, images are synchronously decoded. */ PAINTBG_SYNC_DECODE_IMAGES = 0x02, /** * When this flag is passed, painting will go to the screen so we can * take advantage of the fact that it will be clipped to the viewport. */ PAINTBG_TO_WINDOW = 0x04 }; static void PaintBackground(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aDirtyRect, const nsRect& aBorderArea, PRUint32 aFlags, nsRect* aBGClipRect = nsnull); /** * Same as |PaintBackground|, except using the provided style structs. * This short-circuits the code that ensures that the root element's * background is drawn on the canvas. */ static void PaintBackgroundWithSC(nsPresContext* aPresContext, nsIRenderingContext& aRenderingContext, nsIFrame* aForFrame, const nsRect& aDirtyRect, const nsRect& aBorderArea, nsStyleContext *aStyleContext, const nsStyleBorder& aBorder, PRUint32 aFlags, nsRect* aBGClipRect = nsnull); /** * Returns the rectangle covered by the given background layer image, taking * into account background positioning, sizing, and repetition, but not * clipping. */ static nsRect GetBackgroundLayerRect(nsPresContext* aPresContext, nsIFrame* aForFrame, const nsRect& aBorderArea, const nsStyleBackground& aBackground, const nsStyleBackground::Layer& aLayer); /** * Called by the presShell when painting is finished, so we can clear our * inline background data cache. */ static void DidPaint(); // Draw a border segment in the table collapsing border model without // beveling corners static void DrawTableBorderSegment(nsIRenderingContext& aContext, PRUint8 aBorderStyle, nscolor aBorderColor, const nsStyleBackground* aBGColor, const nsRect& aBorderRect, PRInt32 aAppUnitsPerCSSPixel, PRUint8 aStartBevelSide = 0, nscoord aStartBevelOffset = 0, PRUint8 aEndBevelSide = 0, nscoord aEndBevelOffset = 0); enum { DECORATION_STYLE_NONE = 0, DECORATION_STYLE_SOLID = 1, DECORATION_STYLE_DOTTED = 2, DECORATION_STYLE_DASHED = 3, DECORATION_STYLE_DOUBLE = 4, DECORATION_STYLE_WAVY = 5 }; /** * Function for painting the decoration lines for the text. * NOTE: aPt, aLineSize, aAscent and aOffset are non-rounded device pixels, * not app units. * input: * @param aGfxContext * @param aColor the color of the decoration line * @param aPt the top/left edge of the text * @param aLineSize the width and the height of the decoration * line * @param aAscent the ascent of the text * @param aOffset the offset of the decoration line from * the baseline of the text (if the value is * positive, the line is lifted up) * @param aDecoration which line will be painted. The value can be * NS_STYLE_TEXT_DECORATION_UNDERLINE or * NS_STYLE_TEXT_DECORATION_OVERLINE or * NS_STYLE_TEXT_DECORATION_LINE_THROUGH. * @param aStyle the style of the decoration line (See above * enum names). * @param aDescentLimit If aDescentLimit is zero or larger and the * underline overflows from the descent space, * the underline should be lifted up as far as * possible. Note that this does not mean the * underline never overflows from this * limitation. Because if the underline is * positioned to the baseline or upper, it causes * unreadability. Note that if this is zero * or larger, the underline rect may be shrunken * if it's possible. Therefore, this value is * used for strikeout line and overline too. */ static void PaintDecorationLine(gfxContext* aGfxContext, const nscolor aColor, const gfxPoint& aPt, const gfxSize& aLineSize, const gfxFloat aAscent, const gfxFloat aOffset, const PRUint8 aDecoration, const PRUint8 aStyle, const gfxFloat aDescentLimit = -1.0); /** * Function for getting the decoration line rect for the text. * NOTE: aLineSize, aAscent and aOffset are non-rounded device pixels, * not app units. * input: * @param aPresContext * @param aLineSize the width and the height of the decoration * line * @param aAscent the ascent of the text * @param aOffset the offset of the decoration line from * the baseline of the text (if the value is * positive, the line is lifted up) * @param aDecoration which line will be painted. The value can be * NS_STYLE_TEXT_DECORATION_UNDERLINE or * NS_STYLE_TEXT_DECORATION_OVERLINE or * NS_STYLE_TEXT_DECORATION_LINE_THROUGH. * @param aStyle the style of the decoration line (See above * enum names). * @param aDescentLimit If aDescentLimit is zero or larger and the * underline overflows from the descent space, * the underline should be lifted up as far as * possible. Note that this does not mean the * underline never overflows from this * limitation. Because if the underline is * positioned to the baseline or upper, it causes * unreadability. Note that if this is zero * or larger, the underline rect may be shrunken * if it's possible. Therefore, this value is * used for strikeout line and overline too. * output: * @return the decoration line rect for the input, * the each values are app units. */ static nsRect GetTextDecorationRect(nsPresContext* aPresContext, const gfxSize& aLineSize, const gfxFloat aAscent, const gfxFloat aOffset, const PRUint8 aDecoration, const PRUint8 aStyle, const gfxFloat aDescentLimit = -1.0); protected: static gfxRect GetTextDecorationRectInternal(const gfxPoint& aPt, const gfxSize& aLineSize, const gfxFloat aAscent, const gfxFloat aOffset, const PRUint8 aDecoration, const PRUint8 aStyle, const gfxFloat aDscentLimit); }; /* * nsContextBoxBlur * Creates an 8-bit alpha channel context for callers to draw in, blurs the * contents of that context and applies it as a 1-color mask on a * different existing context. Uses gfxAlphaBoxBlur as its back end. * * You must call Init() first to create a suitable temporary surface to draw * on. You must then draw any desired content onto the given context, then * call DoPaint() to apply the blurred content as a single-color mask. You * can only call Init() once, so objects cannot be reused. * * This is very useful for creating drop shadows or silhouettes. */ class nsContextBoxBlur { public: enum { FORCE_MASK = 0x01 }; /** * Prepares a gfxContext to draw on. Do not call this twice; if you want * to get the gfxContext again use GetContext(). * * @param aRect The coordinates of the surface to create. * All coordinates must be in app units. * This must not include the blur radius, pass * it as the second parameter and everything * is taken care of. * * @param aBlurRadius The blur radius in app units. * * @param aAppUnitsPerDevPixel The number of app units in a device pixel, * for conversion. Most of the time you'll * pass this from the current PresContext if * available. * * @param aDestinationCtx The graphics context to apply the blurred * mask to when you call DoPaint(). Make sure * it is not destroyed before you call * DoPaint(). To set the color of the * resulting blurred graphic mask, you must * set the color on this context before * calling Init(). * * @param aDirtyRect The absolute dirty rect in app units. Used to * optimize the temporary surface size and speed up blur. * * @param aSkipRect An area in device pixels (NOT app units!) to avoid * blurring over, to prevent unnecessary work. * * @param aFlags FORCE_MASK to ensure that the content drawn to the * returned gfxContext is used as a mask, and not * drawn directly to aDestinationCtx. * * @return A blank 8-bit alpha-channel-only graphics context to * draw on, or null on error. Must not be freed. The * context has a device offset applied to it given by * aRect. This means you can use coordinates as if it * were at the desired position at aRect and you don't * need to worry about translating any coordinates to * draw on this temporary surface. * * If aBlurRadius is 0, the returned context is aDestinationCtx and * DoPaint() does nothing, because no blurring is required. Therefore, you * should prepare the destination context as if you were going to draw * directly on it instead of any temporary surface created in this class. */ gfxContext* Init(const nsRect& aRect, nscoord aSpreadRadius, nscoord aBlurRadius, PRInt32 aAppUnitsPerDevPixel, gfxContext* aDestinationCtx, const nsRect& aDirtyRect, const gfxRect* aSkipRect, PRUint32 aFlags = 0); /** * Does the actual blurring/spreading. Users of this object *must* * have called Init() first, then have drawn whatever they want to be * blurred onto the internal gfxContext before calling this. */ void DoEffects(); /** * Does the actual blurring and mask applying. Users of this object *must* * have called Init() first, then have drawn whatever they want to be * blurred onto the internal gfxContext before calling this. */ void DoPaint(); /** * Gets the internal gfxContext at any time. Must not be freed. Avoid * calling this before calling Init() since the context would not be * constructed at that point. */ gfxContext* GetContext(); /** * Get the margin associated with the given blur radius, i.e., the * additional area that might be painted as a result of it. (The * margin for a spread radius is itself, on all sides.) */ static nsMargin GetBlurRadiusMargin(nscoord aBlurRadius, PRInt32 aAppUnitsPerDevPixel); protected: gfxAlphaBoxBlur blur; nsRefPtr mContext; gfxContext* mDestinationCtx; }; #endif /* nsCSSRendering_h___ */