Separate ScrollbarThemeMac into separate files

Source/core/platform/mac/ScrollbarThemeMacOverlayAPI.mm

Index: Source/core/platform/mac/ScrollbarThemeMacOverlayAPI.mm
diff --git a/Source/core/platform/mac/ScrollbarThemeMacOverlayAPI.mm b/Source/core/platform/mac/ScrollbarThemeMacOverlayAPI.mm
new file mode 100644
index 0000000000000000000000000000000000000000..a0ad14f2474d6de7e8f93f9b2bd1fd08437aab8d
--- /dev/null
+++ b/Source/core/platform/mac/ScrollbarThemeMacOverlayAPI.mm
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+/*
+ * Copyright (C) 2013 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 "core/platform/mac/ScrollbarThemeMacOverlayAPI.h"
+
+#include "core/platform/graphics/GraphicsContext.h"
+#include "core/platform/graphics/GraphicsContextStateSaver.h"
+#include "core/platform/mac/LocalCurrentGraphicsContext.h"
+#include "core/platform/mac/NSScrollerImpDetails.h"
+#include "core/platform/ScrollbarThemeClient.h"
+
+namespace WebCore {
+
+typedef HashMap<ScrollbarThemeClient*, RetainPtr<ScrollbarPainter> > ScrollbarPainterMap;
+
+static ScrollbarPainterMap* scrollbarPainterMap()
+{
+    static ScrollbarPainterMap* map = new ScrollbarPainterMap;
+    return map;
+}
+
+static bool supportsExpandedScrollbars()
+{
+    // FIXME: This is temporary until all platforms that support ScrollbarPainter support this part of the API.
+    static bool globalSupportsExpandedScrollbars = [NSClassFromString(@"NSScrollerImp") instancesRespondToSelector:@selector(setExpanded:)];
+    return globalSupportsExpandedScrollbars;
+}
+
+void ScrollbarThemeMacOverlayAPI::registerScrollbar(ScrollbarThemeClient* scrollbar)
+{
+    ScrollbarThemeMacCommon::registerScrollbar(scrollbar);
+
+    bool isHorizontal = scrollbar->orientation() == HorizontalScrollbar;
+    ScrollbarPainter scrollbarPainter = [NSClassFromString(@"NSScrollerImp") scrollerImpWithStyle:recommendedScrollerStyle() controlSize:(NSControlSize)scrollbar->controlSize() horizontal:isHorizontal replacingScrollerImp:nil];
+    scrollbarPainterMap()->add(scrollbar, scrollbarPainter);
+    updateEnabledState(scrollbar);
+    updateScrollbarOverlayStyle(scrollbar);
+}
+
+void ScrollbarThemeMacOverlayAPI::unregisterScrollbar(ScrollbarThemeClient* scrollbar)
+{
+    scrollbarPainterMap()->remove(scrollbar);
+
+    ScrollbarThemeMacCommon::unregisterScrollbar(scrollbar);
+}
+
+void ScrollbarThemeMacOverlayAPI::setNewPainterForScrollbar(ScrollbarThemeClient* scrollbar, ScrollbarPainter newPainter)
+{
+    scrollbarPainterMap()->set(scrollbar, newPainter);
+    updateEnabledState(scrollbar);
+    updateScrollbarOverlayStyle(scrollbar);
+}
+
+ScrollbarPainter ScrollbarThemeMacOverlayAPI::painterForScrollbar(ScrollbarThemeClient* scrollbar)
+{
+    return scrollbarPainterMap()->get(scrollbar).get();
+}
+
+void ScrollbarThemeMacOverlayAPI::paintTrackBackground(GraphicsContext* context, ScrollbarThemeClient* scrollbar, const IntRect& rect) {
+    ASSERT(isScrollbarOverlayAPIAvailable());
+
+    GraphicsContextStateSaver stateSaver(*context);
+    context->translate(rect.x(), rect.y());
+    LocalCurrentGraphicsContext localContext(context);
+
+    CGRect frameRect = scrollbar->frameRect();
+    ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
+    [scrollbarPainter setEnabled:scrollbar->enabled()];
+    [scrollbarPainter setBoundsSize: NSSizeFromCGSize(frameRect.size)];
+
+    NSRect trackRect = NSMakeRect(0, 0, frameRect.size.width, frameRect.size.height);
+    [scrollbarPainter drawKnobSlotInRect:trackRect highlight:NO];
+}
+
+void ScrollbarThemeMacOverlayAPI::paintThumb(GraphicsContext* context, ScrollbarThemeClient* scrollbar, const IntRect& rect) {
+    ASSERT(isScrollbarOverlayAPIAvailable());
+
+    GraphicsContextStateSaver stateSaver(*context);
+    context->translate(rect.x(), rect.y());
+    LocalCurrentGraphicsContext localContext(context);
+
+    ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
+    CGRect frameRect = scrollbar->frameRect();
+    [scrollbarPainter setEnabled:scrollbar->enabled()];
+    [scrollbarPainter setBoundsSize:NSSizeFromCGSize(rect.size())];
+    [scrollbarPainter setDoubleValue:0];
+    [scrollbarPainter setKnobProportion:1];
+    if (scrollbar->enabled())
+        [scrollbarPainter drawKnob];
+
+    // If this state is not set, then moving the cursor over the scrollbar area will only cause the
+    // scrollbar to engorge when moved over the top of the scrollbar area.
+    [scrollbarPainter setBoundsSize: NSSizeFromCGSize(scrollbar->frameRect().size())];
+}
+
+int ScrollbarThemeMacOverlayAPI::scrollbarThickness(ScrollbarControlSize controlSize)
+{
+    ScrollbarPainter scrollbarPainter = [NSClassFromString(@"NSScrollerImp") scrollerImpWithStyle:recommendedScrollerStyle() controlSize:controlSize horizontal:NO replacingScrollerImp:nil];
+    if (supportsExpandedScrollbars())
+        [scrollbarPainter setExpanded:YES];
+    return [scrollbarPainter trackBoxWidth];
+}
+
+bool ScrollbarThemeMacOverlayAPI::usesOverlayScrollbars() const
+{
+    return recommendedScrollerStyle() == NSScrollerStyleOverlay;
+}
+
+void ScrollbarThemeMacOverlayAPI::updateScrollbarOverlayStyle(ScrollbarThemeClient* scrollbar)
+{
+    ScrollbarPainter painter = painterForScrollbar(scrollbar);
+    switch (scrollbar->scrollbarOverlayStyle()) {
+    case ScrollbarOverlayStyleDefault:
+        [painter setKnobStyle:NSScrollerKnobStyleDefault];
+        break;
+    case ScrollbarOverlayStyleDark:
+        [painter setKnobStyle:NSScrollerKnobStyleDark];
+        break;
+    case ScrollbarOverlayStyleLight:
+        [painter setKnobStyle:NSScrollerKnobStyleLight];
+        break;
+    }
+}
+
+ScrollbarButtonsPlacement ScrollbarThemeMacOverlayAPI::buttonsPlacement() const
+{
+    return ScrollbarButtonsNone;
+}
+
+bool ScrollbarThemeMacOverlayAPI::hasThumb(ScrollbarThemeClient* scrollbar)
+{
+    ScrollbarPainter painter = painterForScrollbar(scrollbar);
+    int minLengthForThumb = [painter knobMinLength] + [painter trackOverlapEndInset] + [painter knobOverlapEndInset]
+        + 2 * ([painter trackEndInset] + [painter knobEndInset]);
+    return scrollbar->enabled() && (scrollbar->orientation() == HorizontalScrollbar ?
+             scrollbar->width() :
+             scrollbar->height()) >= minLengthForThumb;
+}
+
+IntRect ScrollbarThemeMacOverlayAPI::backButtonRect(ScrollbarThemeClient* scrollbar, ScrollbarPart part, bool painting)
+{
+    ASSERT(buttonsPlacement() == ScrollbarButtonsNone);
+    return IntRect();
+}
+
+IntRect ScrollbarThemeMacOverlayAPI::forwardButtonRect(ScrollbarThemeClient* scrollbar, ScrollbarPart part, bool painting)
+{
+    ASSERT(buttonsPlacement() == ScrollbarButtonsNone);
+    return IntRect();
+}
+
+IntRect ScrollbarThemeMacOverlayAPI::trackRect(ScrollbarThemeClient* scrollbar, bool painting)
+{
+    ASSERT(!hasButtons(scrollbar));
+    return scrollbar->frameRect();
+}
+
+int ScrollbarThemeMacOverlayAPI::minimumThumbLength(ScrollbarThemeClient* scrollbar)
+{
+    return [painterForScrollbar(scrollbar) knobMinLength];
+}
+
+void ScrollbarThemeMacOverlayAPI::updateEnabledState(ScrollbarThemeClient* scrollbar)
+{
+    [painterForScrollbar(scrollbar) setEnabled:scrollbar->enabled()];
+}
+
+} // namespace WebCore