DevTools: Front-end for platform font inspection

Source/devtools/front_end/PlatformFontsSidebarPane.js

Index: Source/devtools/front_end/PlatformFontsSidebarPane.js
diff --git a/Source/devtools/front_end/PlatformFontsSidebarPane.js b/Source/devtools/front_end/PlatformFontsSidebarPane.js
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+/*
+ * Copyright (C) 2007 Apple Inc.  All rights reserved.

[aandrey, 2013/08/22 13:05:35]

fix license

[lushnikov, 2013/08/22 14:52:39]

Done.

+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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.
+ */
+
+/**
+ * @constructor
+ * @extends {WebInspector.SidebarPane}
+ */
+WebInspector.PlatformFontsSidebarPane = function()
+{
+    WebInspector.SidebarPane.call(this, "Fonts");
+    this.element.addStyleClass("platform-fonts");
+    WebInspector.domAgent.addEventListener(WebInspector.DOMAgent.Events.AttrModified, this._innerUpdate, this);

[aandrey, 2013/08/22 13:05:35]

This can be a performance issue. See https://codereview.chromium.org/22548006/
where I fix slow breadcrumbs. Maybe you also want to listen to the
ElementsTreeUpdated event instead to sync with the elements panel UI updates? Or
at least consider throttling these events (_innerUpdate seems pretty "heavy").

[lushnikov, 2013/08/22 14:52:39]

Added throttling here. Done.

+    WebInspector.domAgent.addEventListener(WebInspector.DOMAgent.Events.AttrRemoved, this._innerUpdate, this);
+}
+
+WebInspector.PlatformFontsSidebarPane.MaxElementsInTextMap = 100;
+
+WebInspector.PlatformFontsSidebarPane.prototype = {
+    /**
+     * @param {WebInspector.DOMNode=} node
+     */
+    update: function(node)
+    {
+        if (!node) {
+            this.element.removeChildren();
+            delete this._node;
+            delete this._platformFonts;
+            delete this._computedStyles;
+            return;
+        }
+        this._node = node;

[aandrey, 2013/08/22 13:05:35]

The old callbacks produced by callbackBarrier may be still alive at this point.
You do not handle the [this._platformFontsCallback, this._computedStyleCallback,
this._render] being called for an old node.

[lushnikov, 2013/08/22 14:52:39]

Done.

+        this._innerUpdate();
+    },
+
+    _innerUpdate: function()
+    {
+        if (!this._node)
+            return;
+        var callbackBarrier = new CallbackBarrier();
+        var platformFontsCallback = callbackBarrier.createCallback(this._platformFontsCallback.bind(this));
+        var computedStyleCallback = callbackBarrier.createCallback(this._computedStyleCallback.bind(this));
+        callbackBarrier.callWhenDone(this._render.bind(this));
+        WebInspector.cssModel.getPlatformFontsForNode(this._node.id, platformFontsCallback);
+        WebInspector.cssModel.getComputedStyleAsync(this._node.id, computedStyleCallback);
+    },
+
+    /**
+     * @param {?Array.<CSSAgent.PlatformFontUsage>} platformFonts
+     */
+    _platformFontsCallback: function(platformFonts)
+    {
+        if (!platformFonts || !platformFonts.length) {
+            delete this._platformFonts;
+            return;
+        }
+
+        this._platformFonts = platformFonts;
+    },
+
+    /**
+     * @param {?WebInspector.CSSStyleDeclaration} computedStyles
+     */
+    _computedStyleCallback: function(computedStyles)
+    {
+        this._computedStyles = computedStyles;
+    },
+
+    _render: function()
+    {
+        this.element.removeChildren();
+        if (!this._platformFonts || !this._computedStyles)
+            return;
+
+        this._platformFonts.sort(function (a, b) {
+            return b.glyphCount - a.glyphCount;
+        }.bind(this));

[aandrey, 2013/08/22 13:05:35]

no need to bind

[lushnikov, 2013/08/22 14:52:39]

Done.

+
+        var cssFontSection = this.element.createChild("div");

[aandrey, 2013/08/22 13:05:35]

this.element.createChild("div", "stats-section monospace");

[lushnikov, 2013/08/22 14:52:39]

Done.

+        cssFontSection.className = "stats-section monospace";
+        var cssFontPrefix = cssFontSection.createChild("span");

[aandrey, 2013/08/22 13:05:35]

ditto

[lushnikov, 2013/08/22 14:52:39]

Done.

+        cssFontPrefix.className = "webkit-css-property";
+        cssFontPrefix.textContent = "font-family";
+        var cssFontColumn = cssFontSection.createChild("span");

[aandrey, 2013/08/22 13:05:35]

use createTextChild()?

[lushnikov, 2013/08/22 14:52:39]

Done.

+        cssFontColumn.textContent = ":";
+        var cssFontValue = cssFontSection.createChild("span");

[aandrey, 2013/08/22 13:05:35]

cssFontSection.createChild("span", "css-font-value");

[lushnikov, 2013/08/22 14:52:39]

Done.

+        cssFontValue.className = "css-font-value";
+        cssFontValue.textContent = this._computedStyles.getLiveProperty("font-family").value + ";";
+
+        var fontStatsSection = document.createElement("div");
+        fontStatsSection.className = "stats-section";
+        for (var i = 0; i < this._platformFonts.length; ++i) {
+            var fontStatElement = fontStatsSection.createChild("div");

[aandrey, 2013/08/22 13:05:35]

ditto here and elsewhere

[lushnikov, 2013/08/22 14:52:39]

Done.

+            fontStatElement.className = "font-stats-item";
+
+            var fontNameElement = fontStatElement.createChild("span");
+            fontNameElement.textContent = this._platformFonts[i].familyName;
+            fontNameElement.className = "font-name";
+
+            var fontDelimeterElement = fontStatElement.createChild("span");
+            fontDelimeterElement.className = "delimeter";
+            fontDelimeterElement.textContent = "—";
+
+            var fontUsageElement = fontStatElement.createChild("span");
+            var usage = this._platformFonts[i].glyphCount;
+            fontUsageElement.textContent = usage + " glyph" + (usage === 1 ? "" : "s");
+            fontUsageElement.className = "font-usage";
+        }
+        this.element.appendChild(fontStatsSection);
+    },
+
+    __proto__: WebInspector.SidebarPane.prototype
+}