自学教程：C++ trackRect函数代码示例

int ScrollbarTheme::trackLength(const ScrollbarThemeClient& scrollbar) {  IntRect constrainedTrackRect =      constrainTrackRectToTrackPieces(scrollbar, trackRect(scrollbar));  return (scrollbar.orientation() == HorizontalScrollbar)             ? constrainedTrackRect.width()             : constrainedTrackRect.height();}

bool ScrollbarTheme::shouldSnapBackToDragOrigin(    const ScrollbarThemeClient& scrollbar,    const PlatformMouseEvent& evt) {  IntPoint mousePosition = scrollbar.convertFromRootFrame(evt.position());  mousePosition.move(scrollbar.x(), scrollbar.y());  return Platform::current()->scrollbarBehavior()->shouldSnapBackToDragOrigin(      mousePosition, trackRect(scrollbar),      scrollbar.orientation() == HorizontalScrollbar);}

IntRect Scrollbar::thumbRect(){    IntRect track = trackRect();    IntRect startTrackRect;    IntRect thumbRect;    IntRect endTrackRect;    splitTrack(track, startTrackRect, thumbRect, endTrackRect);    return thumbRect;}

IntRect ScrollbarTheme::thumbRect(const ScrollbarThemeClient& scrollbar) {  if (!hasThumb(scrollbar))    return IntRect();  IntRect track = trackRect(scrollbar);  IntRect startTrackRect;  IntRect thumbRect;  IntRect endTrackRect;  splitTrack(scrollbar, track, startTrackRect, thumbRect, endTrackRect);  return thumbRect;}

void Scrollbar::paint(GraphicsContext* context, const IntRect& damageRect){    if (!frameRect().intersects(damageRect))        return;    IntRect startTrackRect;    IntRect thumbRect;    IntRect endTrackRect;    splitTrack(trackRect(), startTrackRect, thumbRect, endTrackRect);    if (damageRect.intersects(thumbRect))        paintThumb(context, thumbRect);}

void ScrollbarTheme::invalidatePart(ScrollbarThemeClient* scrollbar, ScrollbarPart part){    if (part == NoPart)        return;    IntRect result;    switch (part) {    case BackButtonStartPart:        result = backButtonRect(scrollbar, BackButtonStartPart, true);        break;    case BackButtonEndPart:        result = backButtonRect(scrollbar, BackButtonEndPart, true);        break;    case ForwardButtonStartPart:        result = forwardButtonRect(scrollbar, ForwardButtonStartPart, true);        break;    case ForwardButtonEndPart:        result = forwardButtonRect(scrollbar, ForwardButtonEndPart, true);        break;    case TrackBGPart:        result = trackRect(scrollbar, true);        break;    case ScrollbarBGPart:        result = scrollbar->frameRect();        break;    default: {        IntRect beforeThumbRect, thumbRect, afterThumbRect;        splitTrack(scrollbar, trackRect(scrollbar), beforeThumbRect, thumbRect, afterThumbRect);        if (part == BackTrackPart)            result = beforeThumbRect;        else if (part == ForwardTrackPart)            result = afterThumbRect;        else            result = thumbRect;    }    }    result.moveBy(-scrollbar->location());    scrollbar->invalidateRect(result);}

// Zoom the note track, centering the pitch at centerY,// amount is 1 for zoom in, and -1 for zoom outvoid NoteTrack::Zoom(int centerY, int amount){   // Construct track rectangle to map pitch to screen coordinates   // Only y and height are needed:   wxRect trackRect(0, GetY(), 1, GetHeight());   PrepareIPitchToY(trackRect);   int centerPitch = YToIPitch(centerY);   // zoom out by changing the pitch height -- a small integer   mPitchHeight += amount;   if (mPitchHeight <= 0) mPitchHeight = 1;   PrepareIPitchToY(trackRect); // update because mPitchHeight changed   int newCenterPitch = YToIPitch(GetY() + GetHeight() / 2);   // center the pitch that the user clicked on   SetBottomNote(mBottomNote + (centerPitch - newCenterPitch));}

void ScrollbarThemeWin::paintTrackPiece(GraphicsContext* gc, ScrollbarThemeClient* scrollbar, const IntRect& rect, ScrollbarPart partType){    bool horz = scrollbar->orientation() == HorizontalScrollbar;    int partId;    if (partType == BackTrackPart)        partId = horz ? SBP_UPPERTRACKHORZ : SBP_UPPERTRACKVERT;    else        partId = horz ? SBP_LOWERTRACKHORZ : SBP_LOWERTRACKVERT;    IntRect alignRect = trackRect(scrollbar, false);    WebKit::WebCanvas* canvas = gc->canvas();    // Draw the track area before/after the thumb on the scroll bar.    WebKit::Platform::current()->themeEngine()->paintScrollbarTrack(canvas, partId, getThemeState(scrollbar, partType), getClassicThemeState(scrollbar, partType), WebKit::WebRect(rect), WebKit::WebRect(alignRect));}

bool ScrollbarThemeChromiumWin::shouldSnapBackToDragOrigin(ScrollbarThemeClient* scrollbar, const PlatformMouseEvent& evt){    // Find the rect within which we shouldn't snap, by expanding the track rect    // in both dimensions.    IntRect rect = trackRect(scrollbar);    const bool horz = scrollbar->orientation() == HorizontalScrollbar;    const int thickness = scrollbarThickness(scrollbar->controlSize());    rect.inflateX((horz ? kOffEndMultiplier : kOffSideMultiplier) * thickness);    rect.inflateY((horz ? kOffSideMultiplier : kOffEndMultiplier) * thickness);    // Convert the event to local coordinates.    IntPoint mousePosition = scrollbar->convertFromContainingWindow(evt.position());    mousePosition.move(scrollbar->x(), scrollbar->y());    // We should snap iff the event is outside our calculated rect.    return !rect.contains(mousePosition);}

void ScrollbarThemeChromiumWin::paintTrackPiece(GraphicsContext* gc, ScrollbarThemeClient* scrollbar, const IntRect& rect, ScrollbarPart partType){    bool horz = scrollbar->orientation() == HorizontalScrollbar;    int partId;    if (partType == BackTrackPart)        partId = horz ? SBP_UPPERTRACKHORZ : SBP_UPPERTRACKVERT;    else        partId = horz ? SBP_LOWERTRACKHORZ : SBP_LOWERTRACKVERT;    IntRect alignRect = trackRect(scrollbar, false);    // Draw the track area before/after the thumb on the scroll bar.    PlatformSupport::paintScrollbarTrack(        gc,        partId,        getThemeState(scrollbar, partType),        getClassicThemeState(scrollbar, partType),        rect,        alignRect);}

ScrollbarPart ScrollbarThemeComposite::hitTest(ScrollbarThemeClient* scrollbar, const PlatformMouseEvent& evt){    ScrollbarPart result = NoPart;    if (!scrollbar->enabled())        return result;    IntPoint mousePosition = scrollbar->convertFromContainingWindow(evt.position());    mousePosition.move(scrollbar->x(), scrollbar->y());        if (!scrollbar->frameRect().contains(mousePosition))        return NoPart;    result = ScrollbarBGPart;    IntRect track = trackRect(scrollbar);    if (track.contains(mousePosition)) {        IntRect beforeThumbRect;        IntRect thumbRect;        IntRect afterThumbRect;        splitTrack(scrollbar, track, beforeThumbRect, thumbRect, afterThumbRect);        if (thumbRect.contains(mousePosition))            result = ThumbPart;        else if (beforeThumbRect.contains(mousePosition))            result = BackTrackPart;        else if (afterThumbRect.contains(mousePosition))            result = ForwardTrackPart;        else            result = TrackBGPart;    } else if (backButtonRect(scrollbar, BackButtonStartPart).contains(mousePosition))        result = BackButtonStartPart;    else if (backButtonRect(scrollbar, BackButtonEndPart).contains(mousePosition))        result = BackButtonEndPart;    else if (forwardButtonRect(scrollbar, ForwardButtonStartPart).contains(mousePosition))        result = ForwardButtonStartPart;    else if (forwardButtonRect(scrollbar, ForwardButtonEndPart).contains(mousePosition))        result = ForwardButtonEndPart;    return result;}

int ScrollbarTheme::thumbThickness(const ScrollbarThemeClient* scrollbar){    IntRect track = trackRect(scrollbar);    return scrollbar->orientation() == HorizontalScrollbar ? track.height() : track.width();}

voidAudioListItem::DrawItem(BView* view, BRect rect, bool complete){	// set background color	rgb_color bgColor;	if (IsSelected())		bgColor = ui_color(B_LIST_SELECTED_BACKGROUND_COLOR);	else		bgColor = ui_color(B_LIST_BACKGROUND_COLOR);	view->SetHighColor(bgColor);	view->SetLowColor(bgColor);	view->FillRect(rect);	// text	BFont font(be_plain_font);	font.SetFace(B_BOLD_FACE);	view->SetFont(&font);	font_height	fheight;	font.GetHeight(&fheight);	BString track("");	if (fTrack < 9)		track.Append("0");	char nummber[4];	snprintf(nummber, sizeof(nummber), "%" B_PRId32, fTrack + 1);	track.Append(nummber);	float trackWidth = font.StringWidth(track.String());	if (!IsSelected()) {		BRect trackRect(rect.LeftTop(),			BPoint(kControlPadding * 2 + trackWidth, rect.bottom));		view->SetHighColor(tint_color(ui_color(B_LIST_BACKGROUND_COLOR), 1.08));		view->FillRect(trackRect);	}	if (IsSelected())		view->SetHighColor(ui_color(B_LIST_SELECTED_ITEM_TEXT_COLOR));	else		view->SetHighColor(ui_color(B_LIST_ITEM_TEXT_COLOR));	view->DrawString(track.String(), BPoint(kControlPadding,	rect.top + fheight.ascent + fheight.descent + fheight.leading));	BString string(GetFilename());	view->TruncateString(&string, B_TRUNCATE_END, Width() - kControlPadding * 4);	font.SetFace(B_REGULAR_FACE);	view->SetFont(&font);	view->DrawString(string.String(), BPoint(kControlPadding * 3 + trackWidth,		rect.top + fheight.ascent + fheight.descent + fheight.leading));	// draw lines	view->SetHighColor(tint_color(ui_color(B_CONTROL_BACKGROUND_COLOR),		B_DARKEN_2_TINT));	view->StrokeLine(rect.LeftBottom(), rect.RightBottom());	view->StrokeLine(BPoint(kControlPadding * 2 + trackWidth, rect.top),		BPoint(kControlPadding * 2 + trackWidth, rect.bottom));}

bool ScrollbarThemeGtk::paint(ScrollbarThemeClient* scrollbar, GraphicsContext* graphicsContext, const IntRect& damageRect){    if (graphicsContext->paintingDisabled())        return false;    // Create the ScrollbarControlPartMask based on the damageRect    ScrollbarControlPartMask scrollMask = NoPart;    IntRect backButtonStartPaintRect;    IntRect backButtonEndPaintRect;    IntRect forwardButtonStartPaintRect;    IntRect forwardButtonEndPaintRect;    if (hasButtons(scrollbar)) {        backButtonStartPaintRect = backButtonRect(scrollbar, BackButtonStartPart, true);        if (damageRect.intersects(backButtonStartPaintRect))            scrollMask |= BackButtonStartPart;        backButtonEndPaintRect = backButtonRect(scrollbar, BackButtonEndPart, true);        if (damageRect.intersects(backButtonEndPaintRect))            scrollMask |= BackButtonEndPart;        forwardButtonStartPaintRect = forwardButtonRect(scrollbar, ForwardButtonStartPart, true);        if (damageRect.intersects(forwardButtonStartPaintRect))            scrollMask |= ForwardButtonStartPart;        forwardButtonEndPaintRect = forwardButtonRect(scrollbar, ForwardButtonEndPart, true);        if (damageRect.intersects(forwardButtonEndPaintRect))            scrollMask |= ForwardButtonEndPart;    }    IntRect trackPaintRect = trackRect(scrollbar, true);    if (damageRect.intersects(trackPaintRect))        scrollMask |= TrackBGPart;    if (m_troughUnderSteppers && (scrollMask & BackButtonStartPart            || scrollMask & BackButtonEndPart            || scrollMask & ForwardButtonStartPart            || scrollMask & ForwardButtonEndPart))        scrollMask |= TrackBGPart;    bool thumbPresent = hasThumb(scrollbar);    IntRect currentThumbRect;    if (thumbPresent) {        IntRect track = trackRect(scrollbar, false);        currentThumbRect = thumbRect(scrollbar, track);        if (damageRect.intersects(currentThumbRect))            scrollMask |= ThumbPart;    }    ScrollbarControlPartMask allButtons = BackButtonStartPart | BackButtonEndPart | ForwardButtonStartPart | ForwardButtonEndPart;    if (scrollMask & TrackBGPart || scrollMask & ThumbPart || scrollMask & allButtons)        paintScrollbarBackground(graphicsContext, scrollbar);        paintTrackBackground(graphicsContext, scrollbar, trackPaintRect);    // Paint the back and forward buttons.    if (scrollMask & BackButtonStartPart)        paintButton(graphicsContext, scrollbar, backButtonStartPaintRect, BackButtonStartPart);    if (scrollMask & BackButtonEndPart)        paintButton(graphicsContext, scrollbar, backButtonEndPaintRect, BackButtonEndPart);    if (scrollMask & ForwardButtonStartPart)        paintButton(graphicsContext, scrollbar, forwardButtonStartPaintRect, ForwardButtonStartPart);    if (scrollMask & ForwardButtonEndPart)        paintButton(graphicsContext, scrollbar, forwardButtonEndPaintRect, ForwardButtonEndPart);    // Paint the thumb.    if (scrollMask & ThumbPart)        paintThumb(graphicsContext, scrollbar, currentThumbRect);    return true;}

bool ScrollbarTheme::shouldSnapBackToDragOrigin(ScrollbarThemeClient* scrollbar, const PlatformMouseEvent& evt){    IntPoint mousePosition = scrollbar->convertFromContainingWindow(evt.position());    mousePosition.move(scrollbar->x(), scrollbar->y());    return Platform::current()->scrollbarBehavior()->shouldSnapBackToDragOrigin(mousePosition, trackRect(scrollbar), scrollbar->orientation() == HorizontalScrollbar);}

bool ScrollbarThemeComposite::paint(ScrollbarThemeClient* scrollbar, GraphicsContext* graphicsContext, const IntRect& damageRect){    // Create the ScrollbarControlPartMask based on the damageRect    ScrollbarControlPartMask scrollMask = NoPart;    IntRect backButtonStartPaintRect;    IntRect backButtonEndPaintRect;    IntRect forwardButtonStartPaintRect;    IntRect forwardButtonEndPaintRect;    if (hasButtons(scrollbar)) {        backButtonStartPaintRect = backButtonRect(scrollbar, BackButtonStartPart, true);        if (damageRect.intersects(backButtonStartPaintRect))            scrollMask |= BackButtonStartPart;        backButtonEndPaintRect = backButtonRect(scrollbar, BackButtonEndPart, true);        if (damageRect.intersects(backButtonEndPaintRect))            scrollMask |= BackButtonEndPart;        forwardButtonStartPaintRect = forwardButtonRect(scrollbar, ForwardButtonStartPart, true);        if (damageRect.intersects(forwardButtonStartPaintRect))            scrollMask |= ForwardButtonStartPart;        forwardButtonEndPaintRect = forwardButtonRect(scrollbar, ForwardButtonEndPart, true);        if (damageRect.intersects(forwardButtonEndPaintRect))            scrollMask |= ForwardButtonEndPart;    }    IntRect startTrackRect;    IntRect thumbRect;    IntRect endTrackRect;    IntRect trackPaintRect = trackRect(scrollbar, true);    if (damageRect.intersects(trackPaintRect))        scrollMask |= TrackBGPart;    bool thumbPresent = hasThumb(scrollbar);    if (thumbPresent) {        IntRect track = trackRect(scrollbar);        splitTrack(scrollbar, track, startTrackRect, thumbRect, endTrackRect);        if (damageRect.intersects(thumbRect))            scrollMask |= ThumbPart;        if (damageRect.intersects(startTrackRect))            scrollMask |= BackTrackPart;        if (damageRect.intersects(endTrackRect))            scrollMask |= ForwardTrackPart;    }    // Paint the scrollbar background (only used by custom CSS scrollbars).    paintScrollbarBackground(graphicsContext, scrollbar);    // Paint the back and forward buttons.    if (scrollMask & BackButtonStartPart)        paintButton(graphicsContext, scrollbar, backButtonStartPaintRect, BackButtonStartPart);    if (scrollMask & BackButtonEndPart)        paintButton(graphicsContext, scrollbar, backButtonEndPaintRect, BackButtonEndPart);    if (scrollMask & ForwardButtonStartPart)        paintButton(graphicsContext, scrollbar, forwardButtonStartPaintRect, ForwardButtonStartPart);    if (scrollMask & ForwardButtonEndPart)        paintButton(graphicsContext, scrollbar, forwardButtonEndPaintRect, ForwardButtonEndPart);        if (scrollMask & TrackBGPart)        paintTrackBackground(graphicsContext, scrollbar, trackPaintRect);        if ((scrollMask & ForwardTrackPart) || (scrollMask & BackTrackPart)) {        // Paint the track pieces above and below the thumb.        if (scrollMask & BackTrackPart)            paintTrackPiece(graphicsContext, scrollbar, startTrackRect, BackTrackPart);        if (scrollMask & ForwardTrackPart)            paintTrackPiece(graphicsContext, scrollbar, endTrackRect, ForwardTrackPart);        paintTickmarks(graphicsContext, scrollbar, trackPaintRect);    }    // Paint the thumb.    if (scrollMask & ThumbPart)        paintThumb(graphicsContext, scrollbar, thumbRect);    return true;}

int ScrollbarThemeComposite::trackPosition(Scrollbar* scrollbar){    IntRect constrainedTrackRect = constrainTrackRectToTrackPieces(scrollbar, trackRect(scrollbar));    return (scrollbar->orientation() == HorizontalScrollbar) ? constrainedTrackRect.x() - scrollbar->x() : constrainedTrackRect.y() - scrollbar->y();}

bool ScrollbarThemeComposite::paint(Scrollbar* scrollbar, GraphicsContext* graphicsContext, const IntRect& damageRect){    // Create the ScrollbarControlPartMask based on the damageRect    ScrollbarControlPartMask scrollMask = NoPart;    IntRect backButtonStartPaintRect;    IntRect backButtonEndPaintRect;    IntRect forwardButtonStartPaintRect;    IntRect forwardButtonEndPaintRect;    if (hasButtons(scrollbar)) {        backButtonStartPaintRect = backButtonRect(scrollbar, BackButtonStartPart, true);        if (damageRect.intersects(backButtonStartPaintRect))            scrollMask |= BackButtonStartPart;        backButtonEndPaintRect = backButtonRect(scrollbar, BackButtonEndPart, true);        if (damageRect.intersects(backButtonEndPaintRect))            scrollMask |= BackButtonEndPart;        forwardButtonStartPaintRect = forwardButtonRect(scrollbar, ForwardButtonStartPart, true);        if (damageRect.intersects(forwardButtonStartPaintRect))            scrollMask |= ForwardButtonStartPart;        forwardButtonEndPaintRect = forwardButtonRect(scrollbar, ForwardButtonEndPart, true);        if (damageRect.intersects(forwardButtonEndPaintRect))            scrollMask |= ForwardButtonEndPart;    }    IntRect startTrackRect;    IntRect thumbRect;    IntRect endTrackRect;    IntRect trackPaintRect = trackRect(scrollbar, true);    if (damageRect.intersects(trackPaintRect))        scrollMask |= TrackBGPart;    bool thumbPresent = hasThumb(scrollbar);    if (thumbPresent) {        IntRect track = trackRect(scrollbar);        splitTrack(scrollbar, track, startTrackRect, thumbRect, endTrackRect);        if (damageRect.intersects(thumbRect))            scrollMask |= ThumbPart;        if (damageRect.intersects(startTrackRect))            scrollMask |= BackTrackPart;        if (damageRect.intersects(endTrackRect))            scrollMask |= ForwardTrackPart;    } #if PLATFORM(WIN)    // FIXME: This API makes the assumption that the custom scrollbar's metrics will match    // the theme's metrics.  This is not a valid assumption.  The ability for a client to paint    // custom scrollbars should be removed once scrollbars can be styled via CSS.    if (Page* page = pageForScrollView(scrollbar->parent())) {        if (page->settings()->shouldPaintCustomScrollbars()) {            float proportion = static_cast<float>(scrollbar->visibleSize()) / scrollbar->totalSize();            float value = scrollbar->currentPos() / static_cast<float>(scrollbar->maximum());            ScrollbarControlState s = 0;            if (scrollbar->client()->isActive())                s |= ActiveScrollbarState;            if (scrollbar->enabled())                s |= EnabledScrollbarState;            if (scrollbar->pressedPart() != NoPart)                s |= PressedScrollbarState;            if (page->chrome()->client()->paintCustomScrollbar(graphicsContext,                                                               scrollbar->frameRect(),                                                                scrollbar->controlSize(),                                                               s,                                                                scrollbar->pressedPart(),                                                                scrollbar->orientation() == VerticalScrollbar,                                                               value,                                                               proportion,                                                               scrollMask))                return true;        }    }#endif    // Paint the scrollbar background (only used by custom CSS scrollbars).    paintScrollbarBackground(graphicsContext, scrollbar);    // Paint the back and forward buttons.    if (scrollMask & BackButtonStartPart)        paintButton(graphicsContext, scrollbar, backButtonStartPaintRect, BackButtonStartPart);    if (scrollMask & BackButtonEndPart)        paintButton(graphicsContext, scrollbar, backButtonEndPaintRect, BackButtonEndPart);    if (scrollMask & ForwardButtonStartPart)        paintButton(graphicsContext, scrollbar, forwardButtonStartPaintRect, ForwardButtonStartPart);    if (scrollMask & ForwardButtonEndPart)        paintButton(graphicsContext, scrollbar, forwardButtonEndPaintRect, ForwardButtonEndPart);        if (scrollMask & TrackBGPart)        paintTrackBackground(graphicsContext, scrollbar, trackPaintRect);        if ((scrollMask & ForwardTrackPart) || (scrollMask & BackTrackPart)) {        // Paint the track pieces above and below the thumb.        if (scrollMask & BackTrackPart)            paintTrackPiece(graphicsContext, scrollbar, startTrackRect, BackTrackPart);        if (scrollMask & ForwardTrackPart)            paintTrackPiece(graphicsContext, scrollbar, endTrackRect, ForwardTrackPart);        paintTickmarks(graphicsContext, scrollbar, trackPaintRect);    }    // Paint the thumb.    if (scrollMask & ThumbPart)        paintThumb(graphicsContext, scrollbar, thumbRect);//.........这里部分代码省略.........