Introduce typeface cache in blink::FontCache

third_party/WebKit/Source/platform/fonts/FontRenderStyle.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "platform/fonts/FontRenderStyle.h"
+
+#include "platform/fonts/FontDescription.h"
+#include "platform/LayoutTestSupport.h"
+#include "wtf/text/WTFString.h"
+#include "public/platform/linux/WebFontRenderStyle.h"
+#include "public/platform/Platform.h"
+#include "public/platform/linux/WebSandboxSupport.h"
+
+namespace blink {
+
+static SkPaint::Hinting skiaHinting = SkPaint::kNormal_Hinting;
+static bool useSkiaAutoHint = true;
+static bool useSkiaBitmaps = true;
+static bool useSkiaAntiAlias = true;
+static bool useSkiaSubpixelRendering = false;
+
+void FontRenderStyle::setHinting(SkPaint::Hinting hinting)
+{
+    skiaHinting = hinting;
+}
+
+void FontRenderStyle::setAutoHint(bool useAutoHint)
+{
+    useSkiaAutoHint = useAutoHint;
+}
+
+void FontRenderStyle::setUseBitmaps(bool useBitmaps)
+{
+    useSkiaBitmaps = useBitmaps;
+}
+
+void FontRenderStyle::setAntiAlias(bool useAntiAlias)
+{
+    useSkiaAntiAlias = useAntiAlias;
+}
+
+void FontRenderStyle::setSubpixelRendering(bool useSubpixelRendering)
+{
+    useSkiaSubpixelRendering = useSubpixelRendering;
+}
+
+void FontRenderStyle::apply(SkPaint* paint, float deviceScaleFactor) const
+{
+    paint->setAntiAlias(useAntiAlias);
+    paint->setHinting(static_cast<SkPaint::Hinting>(hintStyle));
+    paint->setEmbeddedBitmapText(useBitmaps);
+    paint->setAutohinted(useAutoHint);
+    if (useAntiAlias)
+        paint->setLCDRenderText(useSubpixelRendering);
+
+    // Do not enable subpixel text on low-dpi if full hinting is requested.
+    bool useSubpixelText = (paint->getHinting() != SkPaint::kFull_Hinting || deviceScaleFactor > 1.0f);
+
+    // TestRunner specifically toggles the subpixel positioning flag.
+    if (useSubpixelText && !LayoutTestSupport::isRunningLayoutTest())
+        paint->setSubpixelText(true);
+    else
+        paint->setSubpixelText(useSubpixelPositioning);
+}
+
+void FontRenderStyle::querySystemForRenderStyle(WTF::String family, float textSize, SkTypeface::Style typefaceStyle)
+{
+    WebFontRenderStyle style;
+#if OS(ANDROID)
+    style.setDefaults();
+#else
+    // If the font name is missing (i.e. probably a web font) or the sandbox is disabled, use the system defaults.
+    if (!family.length() || !Platform::current()->sandboxSupport()) {
+        style.setDefaults();
+    } else {
+        const int sizeAndStyle = (((int)textSize) << 2) | (typefaceStyle & 3);
+        Platform::current()->sandboxSupport()->getWebFontRenderStyleForStrike(family.utf8().data(), sizeAndStyle, &style);
+    }
+#endif
+    style.toFontRenderStyle(this);
+
+    // Fix FontRenderStyle::NoPreference to actual styles.
+    if (useAntiAlias == FontRenderStyle::NoPreference)
+        useAntiAlias = useSkiaAntiAlias;
+
+    if (!useHinting)
+        hintStyle = SkPaint::kNo_Hinting;
+    else if (useHinting == FontRenderStyle::NoPreference)
+        hintStyle = skiaHinting;
+
+    if (useBitmaps == FontRenderStyle::NoPreference)
+        useBitmaps = useSkiaBitmaps;
+    if (useAutoHint == FontRenderStyle::NoPreference)
+        useAutoHint = useSkiaAutoHint;
+    if (useAntiAlias == FontRenderStyle::NoPreference)
+        useAntiAlias = useSkiaAntiAlias;
+    if (useSubpixelRendering == FontRenderStyle::NoPreference)
+        useSubpixelRendering = useSkiaSubpixelRendering;
+
+    // TestRunner specifically toggles the subpixel positioning flag.
+    if (useSubpixelPositioning == FontRenderStyle::NoPreference
+        || LayoutTestSupport::isRunningLayoutTest())
+        useSubpixelPositioning = FontDescription::subpixelPositioning();
+}
+
+} // namespace blink