DevTools: Changes View

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

+// 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.
+
+/** @typedef {!{lineNumber: number, index: number}} */
+Changes.DiffState;
+
+CodeMirror.defineMode('devtools-diff', function(config, parserConfig) {

[lushnikov, 2017/03/23 22:53:21]

let's have jsdoc

+  var rows = parserConfig.rows || [];
+  var baselineLines = parserConfig.baselineLines;
+  var currentLines = parserConfig.currentLines;
+  var innerMode = CodeMirror.getMode({indentUnit: 2}, parserConfig.mimeType);

[lushnikov, 2017/03/23 22:53:21]

we don't need indent here

+
+  function fastForward(state, baselineLineNumber, currentLineNumber) {

[lushnikov, 2017/03/23 22:53:21]

jsdoc

+    if (baselineLineNumber > state.baselineLineNumber) {
+      fastForwardState(state.baselineState, state.baselineLineNumber, baselineLineNumber, baselineLines);
+      state.baselineLineNumber = baselineLineNumber;
+    }
+    if (currentLineNumber > state.currentLineNumber) {
+      fastForwardState(state.currentState, state.currentLineNumber, currentLineNumber, currentLines);
+      state.currentLineNumber = currentLineNumber;
+    }
+  }
+
+  function fastForwardState(state, from, to, lines) {

[lushnikov, 2017/03/23 22:53:20]

jsdoc

+    var lineNumber = from;
+    while (lineNumber < to && lineNumber < lines.length) {
+      var stream = new CodeMirror.StringStream(lines[lineNumber]);
+      while (!stream.eol()) {
+        innerMode.token(stream, state);
+        stream.start = stream.pos;
+      }
+      lineNumber++;
+    }
+  }
+
+  return {
+    /**
+     * @return {!Changes.DiffState}
+     */
+    startState: function() {
+      return {
+        lineNumber: 0,
+        index: 0,
+        currentLineNumber: 0,
+        baselineLineNumber: 0,
+        currentState: CodeMirror.startState(innerMode),
+        baselineState: CodeMirror.startState(innerMode),
+        mismatch: 0
+      };
+    },
+
+    /**
+     * @param {!{next: function()}} stream
+     * @param {!Changes.DiffState} state
+     * @return {string}
+     */
+    token: function(stream, state) {
+      var row = rows[state.lineNumber];
+      if (!row) {
+        stream.next();
+        return '';
+      }
+      fastForward(state, row.base - 1, row.current - 1);
+      var classes = '';
+      if (state.index === 0)
+        classes += ' line-background-' + row.className + ' line-' + row.className;
+      var chars = row.content[state.index].text.length;
+      if (state.mismatch > 0)
+        chars = state.mismatch;
+      var pos = stream.pos;
+      var innerStyle = state.lastInnerStyle;
+      var innerPos = pos - state.mismatch;
+      if (state.mismatch >= 0) {
+        if (row.className === 'deletion' || row.className === 'addition' || row.className === 'equal') {
+          innerStyle = innerMode.token(stream, row.className === 'deletion' ? state.baselineState : state.currentState);
+          innerPos = stream.pos;
+        } else {
+          innerStyle = '';
+          innerPos = pos + chars;
+        }
+      }
+      stream.pos = Math.min(innerPos, pos + chars);
+      if (innerStyle)
+        classes += ' ' + innerStyle;
+      classes += ' ' + row.content[state.index].className;
+      state.mismatch = pos + chars - innerPos;
+      if (state.mismatch <= 0) {
+        state.index++;
+        state.lastInnerStyle = innerStyle;
+      }
+      if (state.index >= row.content.length) {
+        state.lineNumber++;
+        if (row.className === 'deletion')
+          state.baselineLineNumber++;
+        else
+          state.currentLineNumber++;
+        state.index = 0;
+      }
+      return classes;
+    },
+
+    /**
+     * @param {!Changes.DiffState} state
+     * @return {string}
+     */
+    blankLine: function(state) {
+      var row = rows[state.lineNumber];
+      state.lineNumber++;
+      state.mismatch = 0;
+      state.index = 0;
+      if (!row)
+        return '';
+      if (row.className === 'deletion')
+        state.baselineLineNumber++;
+      else
+        state.currentLineNumber++;
+      var style = '';
+      if (innerMode.blankLine)
+        style = innerMode.blankLine(row.className === 'deletion' ? state.baselineState : state.currentState);
+      return style + ' line-background-' + row.className + ' line-' + row.className;
+    },
+
+    /**
+     * @param {!Changes.DiffState} state
+     * @return {!Changes.DiffState}
+     */
+    copyState: function(state) {
+      var newState = /** @type {!Changes.DiffState} */ ({});
+      for (var i in state)
+        newState[i] = state[i];
+      newState.currentState = CodeMirror.copyState(innerMode, state.currentState);
+      newState.baselineState = CodeMirror.copyState(innerMode, state.baselineState);
+      return newState;
+    }
+  };
+});