WebCore/platform/chromium/ScrollbarThemeChromiumLinux.cpp - platform/external/webkit - Git at Google

 /*
  * Copyright (c) 2008, 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.
  */

 #include "config.h"
 #include "ScrollbarThemeChromiumLinux.h"

 #include "PlatformContextSkia.h"
 #include "PlatformMouseEvent.h"
 #include "RenderTheme.h"
 #include "RenderThemeChromiumLinux.h"
 #include "Scrollbar.h"
 #include "TransformationMatrix.h"

 namespace WebCore {

 ScrollbarTheme* ScrollbarTheme::nativeTheme()
 {
     static ScrollbarThemeChromiumLinux theme;
     return &theme;
 }

 int ScrollbarThemeChromiumLinux::scrollbarThickness(ScrollbarControlSize controlSize)
 {
     return 15;
 }

 static void drawVertLine(SkCanvas* canvas, int x, int y1, int y2, const SkPaint& paint)
 {
     SkIRect skrect;
     skrect.set(x, y1, x + 1, y2 + 1);
     canvas->drawIRect(skrect, paint);
 }

 static void drawHorizLine(SkCanvas* canvas, int x1, int x2, int y, const SkPaint& paint)
 {
     SkIRect skrect;
     skrect.set(x1, y, x2 + 1, y + 1);
     canvas->drawIRect(skrect, paint);
 }

 static void drawBox(SkCanvas* canvas, const IntRect& rect, const SkPaint& paint)
 {
     const int right = rect.x() + rect.width() - 1;
     const int bottom = rect.y() + rect.height() - 1;
     drawHorizLine(canvas, rect.x(), right, rect.y(), paint);
     drawVertLine(canvas, right, rect.y(), bottom, paint);
     drawHorizLine(canvas, rect.x(), right, bottom, paint);
     drawVertLine(canvas, rect.x(), rect.y(), bottom, paint);
 }

 static SkScalar clamp(SkScalar value, SkScalar min, SkScalar max)
 {
     return std::min(std::max(value, min), max);
 }

 static SkColor saturateAndBrighten(SkScalar* hsv,
                                    SkScalar saturateAmount,
                                    SkScalar brightenAmount)
 {
     SkScalar color[3];
     color[0] = hsv[0];
     color[1] = clamp(hsv[1] + saturateAmount, 0.0, 1.0);
     color[2] = clamp(hsv[2] + brightenAmount, 0.0, 1.0);
     return SkHSVToColor(color);
 }

 static SkColor outlineColor(SkScalar* hsv1, SkScalar* hsv2)
 {
     // GTK Theme engines have way too much control over the layout of
     // the scrollbar. We might be able to more closely approximate its
     // look-and-feel, if we sent whole images instead of just colors
     // from the browser to the renderer. But even then, some themes
     // would just break.
     //
     // So, instead, we don't even try to 100% replicate the look of
     // the native scrollbar. We render our own version, but we make
     // sure to pick colors that blend in nicely with the system GTK
     // theme. In most cases, we can just sample a couple of pixels
     // from the system scrollbar and use those colors to draw our
     // scrollbar.
     //
     // This works fine for the track color and the overall thumb
     // color. But it fails spectacularly for the outline color used
     // around the thumb piece.  Not all themes have a clearly defined
     // outline. For some of them it is partially transparent, and for
     // others the thickness is very unpredictable.
     //
     // So, instead of trying to approximate the system theme, we
     // instead try to compute a reasonable looking choice based on the
     // known color of the track and the thumb piece. This is difficult
     // when trying to deal both with high- and low-contrast themes,
     // and both with positive and inverted themes.
     //
     // The following code has been tested to look OK with all of the
     // default GTK themes.
     SkScalar minDiff = clamp((hsv1[1] + hsv2[1]) * 1.2, 0.2, 0.5);
     SkScalar diff = clamp(fabs(hsv1[2] - hsv2[2]) / 2, minDiff, 0.5);

     if (hsv1[2] + hsv2[2] > 1.0)
         diff = -diff;

     return saturateAndBrighten(hsv2, -0.2, diff);
 }

 IntRect ScrollbarThemeChromium::trackRect(Scrollbar* scrollbar, bool)
 {
     IntSize bs = buttonSize(scrollbar);
     int thickness = scrollbarThickness(scrollbar->controlSize());
     if (scrollbar->orientation() == HorizontalScrollbar)
         return IntRect(scrollbar->x() + bs.width(), scrollbar->y(), scrollbar->width(), thickness);
     return IntRect(scrollbar->x(), scrollbar->y() + bs.height(), thickness, scrollbar->height());
 }

 void ScrollbarThemeChromiumLinux::paintTrackPiece(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart partType)
 {
     SkCanvas* const canvas = gc->platformContext()->canvas();
     SkPaint paint;
     SkIRect skrect;

     skrect.set(rect.x(), rect.y(), rect.x() + rect.width(), rect.y() + rect.height());
     SkScalar track_hsv[3];
     SkColorToHSV(RenderThemeChromiumLinux::trackColor(), track_hsv);
     paint.setColor(saturateAndBrighten(track_hsv, 0, 0));
     canvas->drawIRect(skrect, paint);

     SkScalar thumb_hsv[3];
     SkColorToHSV(RenderThemeChromiumLinux::thumbInactiveColor(),
                  thumb_hsv);

     paint.setColor(outlineColor(track_hsv, thumb_hsv));
     drawBox(canvas, rect, paint);
 }

 void ScrollbarThemeChromiumLinux::paintButton(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart part)
 {
     // We don't use buttons
 }

 void ScrollbarThemeChromiumLinux::paintThumb(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect)
 {
     const bool hovered = scrollbar->hoveredPart() == ThumbPart;
     const int midx = rect.x() + rect.width() / 2;
     const int midy = rect.y() + rect.height() / 2;
     const bool vertical = scrollbar->orientation() == VerticalScrollbar;
     SkCanvas* const canvas = gc->platformContext()->canvas();

     SkScalar thumb[3];
     SkColorToHSV(hovered
                  ? RenderThemeChromiumLinux::thumbActiveColor()
                  : RenderThemeChromiumLinux::thumbInactiveColor(),
                  thumb);

     SkPaint paint;
     paint.setColor(saturateAndBrighten(thumb, 0, 0.02));

     SkIRect skrect;
     if (vertical)
         skrect.set(rect.x(), rect.y(), midx + 1, rect.y() + rect.height());
     else
         skrect.set(rect.x(), rect.y(), rect.x() + rect.width(), midy + 1);

     canvas->drawIRect(skrect, paint);

     paint.setColor(saturateAndBrighten(thumb, 0, -0.02));

     if (vertical)
         skrect.set(midx + 1, rect.y(), rect.x() + rect.width(), rect.y() + rect.height());
     else
         skrect.set(rect.x(), midy + 1, rect.x() + rect.width(), rect.y() + rect.height());

     canvas->drawIRect(skrect, paint);

     SkScalar track[3];
     SkColorToHSV(RenderThemeChromiumLinux::trackColor(), track);
     paint.setColor(outlineColor(track, thumb));
     drawBox(canvas, rect, paint);

     if (rect.height() > 10 && rect.width() > 10) {
         const int grippyHalfWidth = 2;
         const int interGrippyOffset = 3;
         if (vertical) {
             drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy - interGrippyOffset, paint);
             drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy,                     paint);
             drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy + interGrippyOffset, paint);
         } else {
             drawVertLine(canvas, midx - interGrippyOffset, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);
             drawVertLine(canvas, midx,                     midy - grippyHalfWidth, midy + grippyHalfWidth, paint);
             drawVertLine(canvas, midx + interGrippyOffset, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);
         }
     }
 }

 bool ScrollbarThemeChromiumLinux::shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent& evt)
 {
     return (evt.shiftKey() && evt.button() == LeftButton) || (evt.button() == MiddleButton);
 }

 IntSize ScrollbarThemeChromiumLinux::buttonSize(Scrollbar* scrollbar)
 {
     // On Linux, we don't use buttons
     return IntSize(0, 0);
 }

 int ScrollbarThemeChromiumLinux::minimumThumbLength(Scrollbar* scrollbar)
 {
     // This matches Firefox on Linux.
     return 2 * scrollbarThickness(scrollbar->controlSize());
 }

 } // namespace WebCore
	/*
	* Copyright (c) 2008, 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.
	*/

	#include "config.h"
	#include "ScrollbarThemeChromiumLinux.h"

	#include "PlatformContextSkia.h"
	#include "PlatformMouseEvent.h"
	#include "RenderTheme.h"
	#include "RenderThemeChromiumLinux.h"
	#include "Scrollbar.h"
	#include "TransformationMatrix.h"

	namespace WebCore {

	ScrollbarTheme* ScrollbarTheme::nativeTheme()
	{
	static ScrollbarThemeChromiumLinux theme;
	return &theme;
	}

	int ScrollbarThemeChromiumLinux::scrollbarThickness(ScrollbarControlSize controlSize)
	{
	return 15;
	}

	static void drawVertLine(SkCanvas* canvas, int x, int y1, int y2, const SkPaint& paint)
	{
	SkIRect skrect;
	skrect.set(x, y1, x + 1, y2 + 1);
	canvas->drawIRect(skrect, paint);
	}

	static void drawHorizLine(SkCanvas* canvas, int x1, int x2, int y, const SkPaint& paint)
	{
	SkIRect skrect;
	skrect.set(x1, y, x2 + 1, y + 1);
	canvas->drawIRect(skrect, paint);
	}

	static void drawBox(SkCanvas* canvas, const IntRect& rect, const SkPaint& paint)
	{
	const int right = rect.x() + rect.width() - 1;
	const int bottom = rect.y() + rect.height() - 1;
	drawHorizLine(canvas, rect.x(), right, rect.y(), paint);
	drawVertLine(canvas, right, rect.y(), bottom, paint);
	drawHorizLine(canvas, rect.x(), right, bottom, paint);
	drawVertLine(canvas, rect.x(), rect.y(), bottom, paint);
	}

	static SkScalar clamp(SkScalar value, SkScalar min, SkScalar max)
	{
	return std::min(std::max(value, min), max);
	}

	static SkColor saturateAndBrighten(SkScalar* hsv,
	SkScalar saturateAmount,
	SkScalar brightenAmount)
	{
	SkScalar color[3];
	color[0] = hsv[0];
	color[1] = clamp(hsv[1] + saturateAmount, 0.0, 1.0);
	color[2] = clamp(hsv[2] + brightenAmount, 0.0, 1.0);
	return SkHSVToColor(color);
	}

	static SkColor outlineColor(SkScalar* hsv1, SkScalar* hsv2)
	{
	// GTK Theme engines have way too much control over the layout of
	// the scrollbar. We might be able to more closely approximate its
	// look-and-feel, if we sent whole images instead of just colors
	// from the browser to the renderer. But even then, some themes
	// would just break.
	//
	// So, instead, we don't even try to 100% replicate the look of
	// the native scrollbar. We render our own version, but we make
	// sure to pick colors that blend in nicely with the system GTK
	// theme. In most cases, we can just sample a couple of pixels
	// from the system scrollbar and use those colors to draw our
	// scrollbar.
	//
	// This works fine for the track color and the overall thumb
	// color. But it fails spectacularly for the outline color used
	// around the thumb piece. Not all themes have a clearly defined
	// outline. For some of them it is partially transparent, and for
	// others the thickness is very unpredictable.
	//
	// So, instead of trying to approximate the system theme, we
	// instead try to compute a reasonable looking choice based on the
	// known color of the track and the thumb piece. This is difficult
	// when trying to deal both with high- and low-contrast themes,
	// and both with positive and inverted themes.
	//
	// The following code has been tested to look OK with all of the
	// default GTK themes.
	SkScalar minDiff = clamp((hsv1[1] + hsv2[1]) * 1.2, 0.2, 0.5);
	SkScalar diff = clamp(fabs(hsv1[2] - hsv2[2]) / 2, minDiff, 0.5);

	if (hsv1[2] + hsv2[2] > 1.0)
	diff = -diff;

	return saturateAndBrighten(hsv2, -0.2, diff);
	}

	IntRect ScrollbarThemeChromium::trackRect(Scrollbar* scrollbar, bool)
	{
	IntSize bs = buttonSize(scrollbar);
	int thickness = scrollbarThickness(scrollbar->controlSize());
	if (scrollbar->orientation() == HorizontalScrollbar)
	return IntRect(scrollbar->x() + bs.width(), scrollbar->y(), scrollbar->width(), thickness);
	return IntRect(scrollbar->x(), scrollbar->y() + bs.height(), thickness, scrollbar->height());
	}

	void ScrollbarThemeChromiumLinux::paintTrackPiece(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart partType)
	{
	SkCanvas* const canvas = gc->platformContext()->canvas();
	SkPaint paint;
	SkIRect skrect;

	skrect.set(rect.x(), rect.y(), rect.x() + rect.width(), rect.y() + rect.height());
	SkScalar track_hsv[3];
	SkColorToHSV(RenderThemeChromiumLinux::trackColor(), track_hsv);
	paint.setColor(saturateAndBrighten(track_hsv, 0, 0));
	canvas->drawIRect(skrect, paint);

	SkScalar thumb_hsv[3];
	SkColorToHSV(RenderThemeChromiumLinux::thumbInactiveColor(),
	thumb_hsv);

	paint.setColor(outlineColor(track_hsv, thumb_hsv));
	drawBox(canvas, rect, paint);
	}

	void ScrollbarThemeChromiumLinux::paintButton(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart part)
	{
	// We don't use buttons
	}

	void ScrollbarThemeChromiumLinux::paintThumb(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect)
	{
	const bool hovered = scrollbar->hoveredPart() == ThumbPart;
	const int midx = rect.x() + rect.width() / 2;
	const int midy = rect.y() + rect.height() / 2;
	const bool vertical = scrollbar->orientation() == VerticalScrollbar;
	SkCanvas* const canvas = gc->platformContext()->canvas();

	SkScalar thumb[3];
	SkColorToHSV(hovered
	? RenderThemeChromiumLinux::thumbActiveColor()
	: RenderThemeChromiumLinux::thumbInactiveColor(),
	thumb);

	SkPaint paint;
	paint.setColor(saturateAndBrighten(thumb, 0, 0.02));

	SkIRect skrect;
	if (vertical)
	skrect.set(rect.x(), rect.y(), midx + 1, rect.y() + rect.height());
	else
	skrect.set(rect.x(), rect.y(), rect.x() + rect.width(), midy + 1);

	canvas->drawIRect(skrect, paint);

	paint.setColor(saturateAndBrighten(thumb, 0, -0.02));

	if (vertical)
	skrect.set(midx + 1, rect.y(), rect.x() + rect.width(), rect.y() + rect.height());
	else
	skrect.set(rect.x(), midy + 1, rect.x() + rect.width(), rect.y() + rect.height());

	canvas->drawIRect(skrect, paint);

	SkScalar track[3];
	SkColorToHSV(RenderThemeChromiumLinux::trackColor(), track);
	paint.setColor(outlineColor(track, thumb));
	drawBox(canvas, rect, paint);

	if (rect.height() > 10 && rect.width() > 10) {
	const int grippyHalfWidth = 2;
	const int interGrippyOffset = 3;
	if (vertical) {
	drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy - interGrippyOffset, paint);
	drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy, paint);
	drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy + interGrippyOffset, paint);
	} else {
	drawVertLine(canvas, midx - interGrippyOffset, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);
	drawVertLine(canvas, midx, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);
	drawVertLine(canvas, midx + interGrippyOffset, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);
	}
	}
	}

	bool ScrollbarThemeChromiumLinux::shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent& evt)
	{
	return (evt.shiftKey() && evt.button() == LeftButton) \|\| (evt.button() == MiddleButton);
	}

	IntSize ScrollbarThemeChromiumLinux::buttonSize(Scrollbar* scrollbar)
	{
	// On Linux, we don't use buttons
	return IntSize(0, 0);
	}

	int ScrollbarThemeChromiumLinux::minimumThumbLength(Scrollbar* scrollbar)
	{
	// This matches Firefox on Linux.
	return 2 * scrollbarThickness(scrollbar->controlSize());
	}

	} // namespace WebCore