DevTools: Changes View

third_party/WebKit/Source/devtools/front_end/changes/ChangesView.js

Index: third_party/WebKit/Source/devtools/front_end/changes/ChangesView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/changes/ChangesView.js b/third_party/WebKit/Source/devtools/front_end/changes/ChangesView.js
new file mode 100644
index 0000000000000000000000000000000000000000..b4078e735bfa45c160215ea02b0e0de998de165d
--- /dev/null
+++ b/third_party/WebKit/Source/devtools/front_end/changes/ChangesView.js
@@ -0,0 +1,296 @@
+// Copyright 2017 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.
+
+Changes.ChangesView = class extends UI.VBox {
+  constructor() {
+    super(true);
+    this.registerRequiredCSS('changes/changesView.css');
+    var splitWidget = new UI.SplitWidget(true /* vertical */, false /* sidebar on left */);
+    var mainWidget = new UI.Widget();
+    splitWidget.setMainWidget(mainWidget);
+    splitWidget.show(this.contentElement);
+
+    this._emptyWidget = new UI.EmptyWidget(Common.UIString('No changes'));
+    this._emptyWidget.show(mainWidget.element);
+
+    this._workspaceDiff = WorkspaceDiff.workspaceDiff();
+    this._changesSidebar = new Changes.ChangesSidebar(this._workspaceDiff);
+    this._changesSidebar.addEventListener(
+        Changes.ChangesSidebar.Events.SelectedUISourceCodeChanged, this._selectedUISourceCodeChanged, this);
+    splitWidget.setSidebarWidget(this._changesSidebar);
+
+    /** @type {?Workspace.UISourceCode} */
+    this._selectedUISourceCode = null;
+
+    /** @type {!Array<!Changes.ChangesView.Row>} */
+    this._diffRows = [];
+
+    this._maxLineDigits = 1;
+
+    this._editor = new TextEditor.CodeMirrorTextEditor({
+      lineNumbers: true,
+      lineWrapping: false,
+      maxHighlightLength: Infinity  // This is to avoid CodeMirror bailing out of highlighting big diffs.
+    });
+    this._editor.setReadOnly(true);
+    this._editor.show(mainWidget.element.createChild('div', 'editor-container'));
+    this._editor.hideWidget();
+
+    this._editor.element.addEventListener('click', this._click.bind(this), false);
+
+    this._toolbar = new UI.Toolbar('changes-toolbar', mainWidget.element);
+    var revertButton = new UI.ToolbarButton(Common.UIString('Revert all changes'), 'largeicon-undo');
+    revertButton.addEventListener(UI.ToolbarButton.Events.Click, this._revert.bind(this));
+    this._toolbar.appendToolbarItem(revertButton);
+    this._diffStats = new UI.ToolbarText('');
+    this._toolbar.appendToolbarItem(this._diffStats);
+    this._toolbar.setEnabled(false);
+
+    this._selectedUISourceCodeChanged();
+  }
+
+  _selectedUISourceCodeChanged() {
+    this._revealUISourceCode(this._changesSidebar.selectedUISourceCode());
+  }
+
+  _revert() {
+    var uiSourceCode = this._selectedUISourceCode;
+    if (!uiSourceCode)
+      return;
+    uiSourceCode.requestOriginalContent().then(original => uiSourceCode.addRevision(original || ''));
+  }
+
+  /**
+   * @param {!Event} event
+   */
+  _click(event) {
+    var selection = this._editor.selection();
+    if (!selection.isEmpty())
+      return;
+    var row = this._diffRows[selection.startLine];
+    Common.Revealer.reveal(
+        this._selectedUISourceCode.uiLocation(row.currentLineNumber - 1, selection.startColumn), false);
+    event.consume(true);
+  }
+
+  /**
+   * @param {?Workspace.UISourceCode} uiSourceCode
+   */
+  _revealUISourceCode(uiSourceCode) {
+    if (this._selectedUISourceCode === uiSourceCode)
+      return;
+
+    if (this._selectedUISourceCode)
+      this._workspaceDiff.unsubscribeFromDiffChange(this._selectedUISourceCode, this._refreshDiff, this);
+    if (uiSourceCode && this.isShowing())
+      this._workspaceDiff.subscribeToDiffChange(uiSourceCode, this._refreshDiff, this);
+
+    this._selectedUISourceCode = uiSourceCode;
+    this._refreshDiff();
+  }
+
+  /**
+   * @override
+   */
+  wasShown() {
+    this._refreshDiff();
+  }
+
+  _refreshDiff() {
+    if (!this.isShowing())
+      return;
+
+    if (!this._selectedUISourceCode) {
+      this._renderDiffRows(null);
+      return;
+    }
+    var uiSourceCode = this._selectedUISourceCode;
+    this._workspaceDiff.requestDiff(uiSourceCode).then(diff => {
+      if (this._selectedUISourceCode !== uiSourceCode)
+        return;
+      this._renderDiffRows(diff);
+    });
+  }
+
+  /**
+   * @param {?Diff.Diff.DiffArray} diff
+   */
+  _renderDiffRows(diff) {
+    this._diffRows = [];
+
+    if (!diff || (diff.length === 1 && diff[0][0] === Diff.Diff.Operation.Equal)) {
+      this._diffStats.setText('');
+      this._toolbar.setEnabled(false);
+      this._editor.hideWidget();
+      this._emptyWidget.showWidget();
+      return;
+    }
+
+    var insertions = 0;
+    var deletions = 0;
+    var currentLineNumber = 0;
+    var baselineLineNumber = 0;
+    var paddingLines = 3;
+
+    for (var i = 0; i < diff.length; ++i) {
+      var token = diff[i];
+      switch (token[0]) {
+        case Diff.Diff.Operation.Equal:
+          this._diffRows.pushAll(createEqualRows(token[1], i === 0, i === diff.length - 1));
+          break;
+        case Diff.Diff.Operation.Insert:
+          for (var line of token[1])
+            this._diffRows.push(createRow(line, Changes.ChangesView.RowType.Addition));
+          insertions += token[1].length;
+          break;
+        case Diff.Diff.Operation.Delete:
+          deletions += token[1].length;
+          if (diff[i + 1] && diff[i + 1][0] === Diff.Diff.Operation.Insert) {
+            i++;
+            this._diffRows.pushAll(createModifyRows(token[1].join('\n'), diff[i][1].join('\n')));
+            insertions += diff[i][1].length;
+          } else {
+            for (var line of token[1])
+              this._diffRows.push(createRow(line, Changes.ChangesView.RowType.Deletion));
+          }
+          break;
+      }
+    }
+
+    this._maxLineDigits = Math.ceil(Math.log10(Math.max(currentLineNumber, baselineLineNumber)));
+
+    this._diffStats.setText(Common.UIString(
+        '%d insertion%s (+), %d deletion%s (-)', insertions, insertions !== 1 ? 's' : '', deletions,
+        deletions !== 1 ? 's' : ''));
+    this._toolbar.setEnabled(true);
+    this._emptyWidget.hideWidget();
+
+    this._editor.operation(() => {
+      this._editor.showWidget();
+      this._editor.setHighlightMode({name: 'devtools-diff', rows: this._diffRows});
+      this._editor.setText(this._diffRows.map(row => row.content.map(t => t.text).join('')).join('\n'));
+      this._editor.setLineNumberFormatter(this._lineFormatter.bind(this));
+    });
+
+    /**
+     * @param {!Array<string>} lines
+     * @param {boolean} atStart
+     * @param {boolean} atEnd
+     * @return {!Array<!Changes.ChangesView.Row>}}
+     */
+    function createEqualRows(lines, atStart, atEnd) {
+      var equalRows = [];
+      if (!atStart) {
+        for (var i = 0; i < paddingLines && i < lines.length; i++)
+          equalRows.push(createRow(lines[i], Changes.ChangesView.RowType.Equal));
+        if (lines.length > paddingLines * 2 + 1 && !atEnd) {
+          equalRows.push(createRow(
+              Common.UIString('( \u2026 Skipping ') + (lines.length - paddingLines * 2) +
+                  Common.UIString(' matching lines \u2026 )'),
+              Changes.ChangesView.RowType.Spacer));
+        }
+      }
+      if (!atEnd) {
+        var start = Math.max(lines.length - paddingLines - 1, atStart ? 0 : paddingLines);
+        var skip = lines.length - paddingLines - 1;
+        if (!atStart)
+          skip -= paddingLines;
+        if (skip > 0) {
+          baselineLineNumber += skip;
+          currentLineNumber += skip;
+        }
+
+        for (var i = start; i < lines.length; i++)
+          equalRows.push(createRow(lines[i], Changes.ChangesView.RowType.Equal));
+      }
+      return equalRows;
+    }
+
+    /**
+     * @param {string} before
+     * @param {string} after
+     * @return {!Array<!Changes.ChangesView.Row>}}
+     */
+    function createModifyRows(before, after) {
+      var internalDiff = Diff.Diff.charDiff(before, after, true /* cleanup diff */);
+      var deletionRows = [createRow('', Changes.ChangesView.RowType.Deletion)];
+      var insertionRows = [createRow('', Changes.ChangesView.RowType.Addition)];
+
+      for (var token of internalDiff) {
+        var text = token[1];
+        var type = token[0];
+        var className = type === Diff.Diff.Operation.Equal ? '' : 'inner-diff';
+        var lines = text.split('\n');
+        for (var i = 0; i < lines.length; i++) {
+          if (i > 0 && type !== Diff.Diff.Operation.Insert)
+            deletionRows.push(createRow('', Changes.ChangesView.RowType.Deletion));
+          if (i > 0 && type !== Diff.Diff.Operation.Delete)
+            insertionRows.push(createRow('', Changes.ChangesView.RowType.Addition));
+          if (!lines[i])
+            continue;
+          if (type !== Diff.Diff.Operation.Insert)
+            deletionRows[deletionRows.length - 1].content.push({text: lines[i], className});
+          if (type !== Diff.Diff.Operation.Delete)
+            insertionRows[insertionRows.length - 1].content.push({text: lines[i], className});
+        }
+      }
+      return deletionRows.concat(insertionRows);
+    }
+
+    /**
+     * @param {string} text
+     * @param {!Changes.ChangesView.RowType} type
+     * @return {!Changes.ChangesView.Row}
+     */
+    function createRow(text, type) {
+      if (type === Changes.ChangesView.RowType.Addition)
+        currentLineNumber++;
+      if (type === Changes.ChangesView.RowType.Deletion)
+        baselineLineNumber++;
+      if (type === Changes.ChangesView.RowType.Equal) {
+        baselineLineNumber++;
+        currentLineNumber++;
+      }
+
+      return {baselineLineNumber, currentLineNumber, content: text ? [{text, className: 'inner-diff'}] : [], type};
+    }
+  }
+
+  /**
+   * @param {number} lineNumber
+   * @return {string}
+   */
+  _lineFormatter(lineNumber) {
+    var row = this._diffRows[lineNumber - 1];
+    var showBaseNumber = row.type === Changes.ChangesView.RowType.Deletion;
+    var showCurrentNumber = row.type === Changes.ChangesView.RowType.Addition;
+    if (row.type === Changes.ChangesView.RowType.Equal) {
+      showBaseNumber = true;
+      showCurrentNumber = true;
+    }
+    var base = showBaseNumber ? numberToStringWithSpacesPadding(row.baselineLineNumber, this._maxLineDigits) :
+                                spacesPadding(this._maxLineDigits);
+    var current = showCurrentNumber ? numberToStringWithSpacesPadding(row.currentLineNumber, this._maxLineDigits) :
+                                      spacesPadding(this._maxLineDigits);
+    return base + spacesPadding(1) + current;
+  }
+};
+
+/**
+ * @typedef {!{
+ *  baselineLineNumber: number,
+ *  currentLineNumber: number,
+ *  content: !Array<!{text: string, className: string}>,
+ *  type: !Changes.ChangesView.RowType
+ * }}
+ */
+Changes.ChangesView.Row;
+
+/** @enum {string} */
+Changes.ChangesView.RowType = {
+  Deletion: 'deletion',
+  Addition: 'addition',
+  Equal: 'equal',
+  Spacer: 'spacer'
+};