DevTools: introduce object previews experiment

third_party/WebKit/Source/devtools/front_end/components/ObjectPropertiesSection.js

Index: third_party/WebKit/Source/devtools/front_end/components/ObjectPropertiesSection.js
diff --git a/third_party/WebKit/Source/devtools/front_end/components/ObjectPropertiesSection.js b/third_party/WebKit/Source/devtools/front_end/components/ObjectPropertiesSection.js
index 21f0f9756b13289e5e1b850ea0b01415ea575242..13124125924eeb437ab55b9cf809c7be0ca7ea1f 100644
--- a/third_party/WebKit/Source/devtools/front_end/components/ObjectPropertiesSection.js
+++ b/third_party/WebKit/Source/devtools/front_end/components/ObjectPropertiesSection.js
@@ -220,15 +220,17 @@ Components.ObjectPropertiesSection = class extends UI.TreeOutlineInShadow {
    * @param {boolean} wasThrown
    * @param {!Element=} parentElement
    * @param {!Components.Linkifier=} linkifier
+   * @param {boolean=} hidePreview

[dgozman, 2017/01/13 02:55:41]

Let's be consistent with the reset and make this a required parameter
'showPreview'.

[luoe, 2017/01/13 23:20:12]

Done.

    * @return {!Element}
    */
-  static createValueElementWithCustomSupport(value, wasThrown, parentElement, linkifier) {
+  static createValueElementWithCustomSupport(value, wasThrown, parentElement, linkifier, hidePreview) {
     if (value.customPreview()) {
       var result = (new Components.CustomPreviewComponent(value)).element;
       result.classList.add('object-properties-section-custom-section');
       return result;
     }
-    return Components.ObjectPropertiesSection.createValueElement(value, wasThrown, parentElement, linkifier);
+    return Components.ObjectPropertiesSection.createValueElement(
+        value, wasThrown, parentElement, linkifier, hidePreview);
   }
 
   /**
@@ -236,9 +238,10 @@ Components.ObjectPropertiesSection = class extends UI.TreeOutlineInShadow {
    * @param {boolean} wasThrown
    * @param {!Element=} parentElement
    * @param {!Components.Linkifier=} linkifier
+   * @param {boolean=} hidePreview
    * @return {!Element}
    */
-  static createValueElement(value, wasThrown, parentElement, linkifier) {
+  static createValueElement(value, wasThrown, parentElement, linkifier, hidePreview) {
     var valueElement;
     var type = value.type;
     var subtype = value.subtype;
@@ -261,8 +264,13 @@ Components.ObjectPropertiesSection = class extends UI.TreeOutlineInShadow {
         parentElement.classList.add('hbox');
     } else {
       valueElement = createElementWithClass('span', 'object-value-' + (subtype || type));
-      valueElement.setTextContentTruncatedIfNeeded(description);
       valueElement.title = description || '';
+      if (Runtime.experiments.isEnabled('objectPreviews') && value.preview && !hidePreview) {
+        var previewFormatter = new Components.RemoteObjectPreviewFormatter();
+        previewFormatter.appendObjectPreview(valueElement, value.preview);
+      } else {
+        valueElement.setTextContentTruncatedIfNeeded(description);
+      }
     }
 
     if (wasThrown) {
@@ -546,10 +554,11 @@ Components.ObjectPropertyTreeElement = class extends UI.TreeElement {
           treeElement, properties, internalProperties, skipProto, targetValue || value, linkifier, emptyPlaceholder);
     }
 
+    var generatePreview = Runtime.experiments.isEnabled('objectPreviews');
     if (flattenProtoChain)
-      value.getAllProperties(false, callback);
+      value.getAllProperties(false, generatePreview, callback);
     else
-      SDK.RemoteObject.loadFromObjectPerProto(value, callback);
+      SDK.RemoteObject.loadFromObjectPerProto(value, generatePreview, callback);
   }
 
   /**
@@ -781,8 +790,9 @@ Components.ObjectPropertyTreeElement = class extends UI.TreeElement {
     separatorElement.textContent = ': ';
 
     if (this.property.value) {
+      var hidePreview = this.property.name === '__proto__';
       this.valueElement = Components.ObjectPropertiesSection.createValueElementWithCustomSupport(
-          this.property.value, this.property.wasThrown, this.listItemElement, this._linkifier);
+          this.property.value, this.property.wasThrown, this.listItemElement, this._linkifier, hidePreview);
       this.valueElement.addEventListener('contextmenu', this._contextMenuFired.bind(this, this.property), false);
     } else if (this.property.getter) {
       this.valueElement = Components.ObjectPropertyTreeElement.createRemoteObjectAccessorPropertySpan(
@@ -1166,7 +1176,8 @@ Components.ArrayGroupingTreeElement = class extends UI.TreeElement {
     function processArrayFragment(arrayFragment, wasThrown) {
       if (!arrayFragment || wasThrown)
         return;
-      arrayFragment.getAllProperties(false, processProperties.bind(this));
+      arrayFragment.getAllProperties(
+          false, Runtime.experiments.isEnabled('objectPreviews'), processProperties.bind(this));
     }
 
     /** @this {Components.ArrayGroupingTreeElement} */
@@ -1224,7 +1235,7 @@ Components.ArrayGroupingTreeElement = class extends UI.TreeElement {
     function processObjectFragment(arrayFragment, wasThrown) {
       if (!arrayFragment || wasThrown)
         return;
-      arrayFragment.getOwnProperties(processProperties.bind(this));
+      arrayFragment.getOwnProperties(Runtime.experiments.isEnabled('objectPreviews'), processProperties.bind(this));
     }
 
     /**