blob: 65a56f04fe453c845e0ae469694794436feeffa8 [file] [log] [blame]
/**
* @license
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the 'License');
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an 'AS IS' BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
(function(window, GrDiffGroup, GrDiffLine) {
'use strict';
// Prevent redefinition.
if (window.GrDiffBuilder) { return; }
/**
* In JS, unicode code points above 0xFFFF occupy two elements of a string.
* For example '𐀏'.length is 2. An occurence of such a code point is called a
* surrogate pair.
*
* This regex segments a string along tabs ('\t') and surrogate pairs, since
* these are two cases where '1 char' does not automatically imply '1 column'.
*
* TODO: For human languages whose orthographies use combining marks, this
* approach won't correctly identify the grapheme boundaries. In those cases,
* a grapheme consists of multiple code points that should count as only one
* character against the column limit. Getting that correct (if it's desired)
* is probably beyond the limits of a regex, but there are nonstandard APIs to
* do this, and proposed (but, as of Nov 2017, unimplemented) standard APIs.
*
* Further reading:
* On Unicode in JS: https://mathiasbynens.be/notes/javascript-unicode
* Graphemes: http://unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries
* A proposed JS API: https://github.com/tc39/proposal-intl-segmenter
*/
const REGEX_TAB_OR_SURROGATE_PAIR = /\t|[\uD800-\uDBFF][\uDC00-\uDFFF]/;
function GrDiffBuilder(diff, prefs, outputEl, layers) {
this._diff = diff;
this._prefs = prefs;
this._outputEl = outputEl;
this.groups = [];
this._blameInfo = null;
this.layers = layers || [];
if (isNaN(prefs.tab_size) || prefs.tab_size <= 0) {
throw Error('Invalid tab size from preferences.');
}
if (isNaN(prefs.line_length) || prefs.line_length <= 0) {
throw Error('Invalid line length from preferences.');
}
for (const layer of this.layers) {
if (layer.addListener) {
layer.addListener(this._handleLayerUpdate.bind(this));
}
}
}
GrDiffBuilder.GroupType = {
ADDED: 'b',
BOTH: 'ab',
REMOVED: 'a',
};
GrDiffBuilder.Highlights = {
ADDED: 'edit_b',
REMOVED: 'edit_a',
};
GrDiffBuilder.Side = {
LEFT: 'left',
RIGHT: 'right',
};
GrDiffBuilder.ContextButtonType = {
ABOVE: 'above',
BELOW: 'below',
ALL: 'all',
};
const PARTIAL_CONTEXT_AMOUNT = 10;
/**
* Abstract method
*
* @param {string} outputEl
* @param {number} fontSize
*/
GrDiffBuilder.prototype.addColumns = function() {
throw Error('Subclasses must implement addColumns');
};
/**
* Abstract method
*
* @param {Object} group
*/
GrDiffBuilder.prototype.buildSectionElement = function() {
throw Error('Subclasses must implement buildSectionElement');
};
GrDiffBuilder.prototype.emitGroup = function(group, opt_beforeSection) {
const element = this.buildSectionElement(group);
this._outputEl.insertBefore(element, opt_beforeSection);
group.element = element;
};
GrDiffBuilder.prototype.renderSection = function(element) {
for (let i = 0; i < this.groups.length; i++) {
const group = this.groups[i];
if (group.element === element) {
const newElement = this.buildSectionElement(group);
group.element.parentElement.replaceChild(newElement, group.element);
group.element = newElement;
break;
}
}
};
GrDiffBuilder.prototype.getGroupsByLineRange = function(
startLine, endLine, opt_side) {
const groups = [];
for (let i = 0; i < this.groups.length; i++) {
const group = this.groups[i];
if (group.lines.length === 0) {
continue;
}
let groupStartLine = 0;
let groupEndLine = 0;
if (opt_side) {
groupStartLine = group.lineRange[opt_side].start;
groupEndLine = group.lineRange[opt_side].end;
}
if (groupStartLine === 0) { // Line was removed or added.
groupStartLine = groupEndLine;
}
if (groupEndLine === 0) { // Line was removed or added.
groupEndLine = groupStartLine;
}
if (startLine <= groupEndLine && endLine >= groupStartLine) {
groups.push(group);
}
}
return groups;
};
GrDiffBuilder.prototype.getContentByLine = function(lineNumber, opt_side,
opt_root) {
const root = Polymer.dom(opt_root || this._outputEl);
const sideSelector = opt_side ? ('.' + opt_side) : '';
return root.querySelector('td.lineNum[data-value="' + lineNumber +
'"]' + sideSelector + ' ~ td.content .contentText');
};
/**
* Find line elements or line objects by a range of line numbers and a side.
*
* @param {number} start The first line number
* @param {number} end The last line number
* @param {string} opt_side The side of the range. Either 'left' or 'right'.
* @param {!Array<GrDiffLine>} out_lines The output list of line objects. Use
* null if not desired.
* @param {!Array<HTMLElement>} out_elements The output list of line elements.
* Use null if not desired.
*/
GrDiffBuilder.prototype.findLinesByRange = function(start, end, opt_side,
out_lines, out_elements) {
const groups = this.getGroupsByLineRange(start, end, opt_side);
for (const group of groups) {
let content = null;
for (const line of group.lines) {
if ((opt_side === 'left' && line.type === GrDiffLine.Type.ADD) ||
(opt_side === 'right' && line.type === GrDiffLine.Type.REMOVE)) {
continue;
}
const lineNumber = opt_side === 'left' ?
line.beforeNumber : line.afterNumber;
if (lineNumber < start || lineNumber > end) { continue; }
if (out_lines) { out_lines.push(line); }
if (out_elements) {
if (content) {
content = this._getNextContentOnSide(content, opt_side);
} else {
content = this.getContentByLine(lineNumber, opt_side,
group.element);
}
if (content) { out_elements.push(content); }
}
}
}
};
/**
* Re-renders the DIV.contentText elements for the given side and range of
* diff content.
*/
GrDiffBuilder.prototype._renderContentByRange = function(start, end, side) {
const lines = [];
const elements = [];
let line;
let el;
this.findLinesByRange(start, end, side, lines, elements);
for (let i = 0; i < lines.length; i++) {
line = lines[i];
el = elements[i];
if (!el) {
// Cannot re-render an element if it does not exist. This can happen
// if lines are collapsed and not visible on the page yet.
continue;
}
const lineNumberEl = this._getLineNumberEl(el, side);
el.parentElement.replaceChild(
this._createTextEl(lineNumberEl, line, side).firstChild,
el);
}
};
GrDiffBuilder.prototype.getSectionsByLineRange = function(
startLine, endLine, opt_side) {
return this.getGroupsByLineRange(startLine, endLine, opt_side).map(
group => { return group.element; });
};
// TODO(wyatta): Move this completely into the processor.
GrDiffBuilder.prototype._insertContextGroups = function(groups, lines,
hiddenRange) {
const linesBeforeCtx = lines.slice(0, hiddenRange[0]);
const hiddenLines = lines.slice(hiddenRange[0], hiddenRange[1]);
const linesAfterCtx = lines.slice(hiddenRange[1]);
if (linesBeforeCtx.length > 0) {
groups.push(new GrDiffGroup(GrDiffGroup.Type.BOTH, linesBeforeCtx));
}
const ctxLine = new GrDiffLine(GrDiffLine.Type.CONTEXT_CONTROL);
ctxLine.contextGroup =
new GrDiffGroup(GrDiffGroup.Type.BOTH, hiddenLines);
groups.push(new GrDiffGroup(GrDiffGroup.Type.CONTEXT_CONTROL,
[ctxLine]));
if (linesAfterCtx.length > 0) {
groups.push(new GrDiffGroup(GrDiffGroup.Type.BOTH, linesAfterCtx));
}
};
GrDiffBuilder.prototype._createContextControl = function(section, line) {
if (!line.contextGroup || !line.contextGroup.lines.length) {
return null;
}
const td = this._createElement('td');
const showPartialLinks =
line.contextGroup.lines.length > PARTIAL_CONTEXT_AMOUNT;
if (showPartialLinks) {
td.appendChild(this._createContextButton(
GrDiffBuilder.ContextButtonType.ABOVE, section, line));
td.appendChild(document.createTextNode(' - '));
}
td.appendChild(this._createContextButton(
GrDiffBuilder.ContextButtonType.ALL, section, line));
if (showPartialLinks) {
td.appendChild(document.createTextNode(' - '));
td.appendChild(this._createContextButton(
GrDiffBuilder.ContextButtonType.BELOW, section, line));
}
return td;
};
GrDiffBuilder.prototype._createContextButton = function(type, section, line) {
const contextLines = line.contextGroup.lines;
const context = PARTIAL_CONTEXT_AMOUNT;
const button = this._createElement('gr-button', 'showContext');
button.setAttribute('link', true);
button.setAttribute('no-uppercase', true);
let text;
const groups = []; // The groups that replace this one if tapped.
if (type === GrDiffBuilder.ContextButtonType.ALL) {
text = 'Show ' + contextLines.length + ' common line';
if (contextLines.length > 1) { text += 's'; }
groups.push(line.contextGroup);
} else if (type === GrDiffBuilder.ContextButtonType.ABOVE) {
text = '+' + context + '↑';
this._insertContextGroups(groups, contextLines,
[context, contextLines.length]);
} else if (type === GrDiffBuilder.ContextButtonType.BELOW) {
text = '+' + context + '↓';
this._insertContextGroups(groups, contextLines,
[0, contextLines.length - context]);
}
Polymer.dom(button).textContent = text;
button.addEventListener('tap', e => {
e.detail = {
groups,
section,
};
// Let it bubble up the DOM tree.
});
return button;
};
GrDiffBuilder.prototype._createLineEl = function(
line, number, type, opt_class) {
const td = this._createElement('td');
if (opt_class) {
td.classList.add(opt_class);
}
if (line.type === GrDiffLine.Type.REMOVE) {
td.setAttribute('aria-label', `${number} removed`);
} else if (line.type === GrDiffLine.Type.ADD) {
td.setAttribute('aria-label', `${number} added`);
}
if (line.type === GrDiffLine.Type.BLANK) {
return td;
} else if (line.type === GrDiffLine.Type.CONTEXT_CONTROL) {
td.classList.add('contextLineNum');
td.setAttribute('data-value', '@@');
td.textContent = '@@';
} else if (line.type === GrDiffLine.Type.BOTH || line.type === type) {
td.classList.add('lineNum');
td.setAttribute('data-value', number);
td.textContent = number === 'FILE' ? 'File' : number;
}
return td;
};
GrDiffBuilder.prototype._createTextEl = function(
lineNumberEl, line, opt_side) {
const td = this._createElement('td');
if (line.type !== GrDiffLine.Type.BLANK) {
td.classList.add('content');
}
td.classList.add(line.type);
const lineLimit =
!this._prefs.line_wrapping ? this._prefs.line_length : Infinity;
const contentText =
this._formatText(line.text, this._prefs.tab_size, lineLimit);
if (opt_side) {
contentText.setAttribute('data-side', opt_side);
}
for (const layer of this.layers) {
layer.annotate(contentText, lineNumberEl, line);
}
td.appendChild(contentText);
return td;
};
/**
* Returns a 'div' element containing the supplied |text| as its innerText,
* with '\t' characters expanded to a width determined by |tabSize|, and the
* text wrapped at column |lineLimit|, which may be Infinity if no wrapping is
* desired.
*
* @param {string} text The text to be formatted.
* @param {number} tabSize The width of each tab stop.
* @param {number} lineLimit The column after which to wrap lines.
* @return {HTMLElement}
*/
GrDiffBuilder.prototype._formatText = function(text, tabSize, lineLimit) {
const contentText = this._createElement('div', 'contentText');
let columnPos = 0;
let textOffset = 0;
for (const segment of text.split(REGEX_TAB_OR_SURROGATE_PAIR)) {
if (segment) {
// |segment| contains only normal characters. If |segment| doesn't fit
// entirely on the current line, append chunks of |segment| followed by
// line breaks.
let rowStart = 0;
let rowEnd = lineLimit - columnPos;
while (rowEnd < segment.length) {
contentText.appendChild(
document.createTextNode(segment.substring(rowStart, rowEnd)));
contentText.appendChild(this._createElement('span', 'br'));
columnPos = 0;
rowStart = rowEnd;
rowEnd += lineLimit;
}
// Append the last part of |segment|, which fits on the current line.
contentText.appendChild(
document.createTextNode(segment.substring(rowStart)));
columnPos += (segment.length - rowStart);
textOffset += segment.length;
}
if (textOffset < text.length) {
// Handle the special character at |textOffset|.
if (text.startsWith('\t', textOffset)) {
// Append a single '\t' character.
let effectiveTabSize = tabSize - (columnPos % tabSize);
if (columnPos + effectiveTabSize > lineLimit) {
contentText.appendChild(this._createElement('span', 'br'));
columnPos = 0;
effectiveTabSize = tabSize;
}
contentText.appendChild(this._getTabWrapper(effectiveTabSize));
columnPos += effectiveTabSize;
textOffset++;
} else {
// Append a single surrogate pair.
if (columnPos >= lineLimit) {
contentText.appendChild(this._createElement('span', 'br'));
columnPos = 0;
}
contentText.appendChild(document.createTextNode(
text.substring(textOffset, textOffset + 2)));
textOffset += 2;
columnPos += 1;
}
}
}
return contentText;
};
/**
* Returns a <span> element holding a '\t' character, that will visually
* occupy |tabSize| many columns.
*
* @param {number} tabSize The effective size of this tab stop.
* @return {HTMLElement}
*/
GrDiffBuilder.prototype._getTabWrapper = function(tabSize) {
// Force this to be a number to prevent arbitrary injection.
const result = this._createElement('span', 'tab');
result.style['tab-size'] = tabSize;
result.style['-moz-tab-size'] = tabSize;
result.innerText = '\t';
return result;
};
GrDiffBuilder.prototype._createElement = function(tagName, classStr) {
const el = document.createElement(tagName);
// When Shady DOM is being used, these classes are added to account for
// Polymer's polyfill behavior. In order to guarantee sufficient
// specificity within the CSS rules, these are added to every element.
// Since the Polymer DOM utility functions (which would do this
// automatically) are not being used for performance reasons, this is
// done manually.
el.classList.add('style-scope', 'gr-diff');
if (classStr) {
for (const className of classStr.split(' ')) {
el.classList.add(className);
}
}
return el;
};
GrDiffBuilder.prototype._handleLayerUpdate = function(start, end, side) {
this._renderContentByRange(start, end, side);
};
/**
* Finds the next DIV.contentText element following the given element, and on
* the same side. Will only search within a group.
*
* @param {HTMLElement} content
* @param {string} side Either 'left' or 'right'
* @return {HTMLElement}
*/
GrDiffBuilder.prototype._getNextContentOnSide = function(content, side) {
throw Error('Subclasses must implement _getNextContentOnSide');
};
/**
* Determines whether the given group is either totally an addition or totally
* a removal.
*
* @param {!Object} group (GrDiffGroup)
* @return {boolean}
*/
GrDiffBuilder.prototype._isTotal = function(group) {
return group.type === GrDiffGroup.Type.DELTA &&
(!group.adds.length || !group.removes.length) &&
!(!group.adds.length && !group.removes.length);
};
/**
* Set the blame information for the diff. For any already-rendered line,
* re-render its blame cell content.
*
* @param {Object} blame
*/
GrDiffBuilder.prototype.setBlame = function(blame) {
this._blameInfo = blame;
// TODO(wyatta): make this loop asynchronous.
for (const commit of blame) {
for (const range of commit.ranges) {
for (let i = range.start; i <= range.end; i++) {
// TODO(wyatta): this query is expensive, but, when traversing a
// range, the lines are consecutive, and given the previous blame
// cell, the next one can be reached cheaply.
const el = this._getBlameByLineNum(i);
if (!el) { continue; }
// Remove the element's children (if any).
while (el.hasChildNodes()) {
el.removeChild(el.lastChild);
}
const blame = this._getBlameForBaseLine(i, commit);
el.appendChild(blame);
}
}
}
};
/**
* Find the blame cell for a given line number.
*
* @param {number} lineNum
* @return {HTMLTableDataCellElement}
*/
GrDiffBuilder.prototype._getBlameByLineNum = function(lineNum) {
const root = Polymer.dom(this._outputEl);
return root.querySelector(`td.blame[data-line-number="${lineNum}"]`);
};
/**
* Given a base line number, return the commit containing that line in the
* current set of blame information. If no blame information has been
* provided, null is returned.
*
* @param {number} lineNum
* @return {Object} The commit information.
*/
GrDiffBuilder.prototype._getBlameCommitForBaseLine = function(lineNum) {
if (!this._blameInfo) { return null; }
for (const blameCommit of this._blameInfo) {
for (const range of blameCommit.ranges) {
if (range.start <= lineNum && range.end >= lineNum) {
return blameCommit;
}
}
}
return null;
};
/**
* Given the number of a base line, get the content for the blame cell of that
* line. If there is no blame information for that line, returns null.
*
* @param {number} lineNum
* @param {Object=} opt_commit Optionally provide the commit object, so that
* it does not need to be searched.
* @return {HTMLSpanElement}
*/
GrDiffBuilder.prototype._getBlameForBaseLine = function(lineNum, opt_commit) {
const commit = opt_commit || this._getBlameCommitForBaseLine(lineNum);
if (!commit) { return null; }
const isStartOfRange = commit.ranges.some(r => r.start === lineNum);
const date = (new Date(commit.time * 1000)).toLocaleDateString();
const blameNode = this._createElement('span',
isStartOfRange ? 'startOfRange' : '');
const shaNode = this._createElement('span', 'sha');
shaNode.innerText = commit.id.substr(0, 7);
blameNode.appendChild(shaNode);
blameNode.append(` on ${date} by ${commit.author}`);
return blameNode;
};
/**
* Create a blame cell for the given base line. Blame information will be
* included in the cell if available.
*
* @param {GrDiffLine} line
* @return {HTMLTableDataCellElement}
*/
GrDiffBuilder.prototype._createBlameCell = function(line) {
const blameTd = this._createElement('td', 'blame');
blameTd.setAttribute('data-line-number', line.beforeNumber);
if (line.beforeNumber) {
const content = this._getBlameForBaseLine(line.beforeNumber);
if (content) {
blameTd.appendChild(content);
}
}
return blameTd;
};
/**
* Finds the line number element given the content element by walking up the
* DOM tree to the diff row and then querying for a .lineNum element on the
* requested side.
*
* TODO(brohlfs): Consolidate this with getLineEl... methods in html file.
*/
GrDiffBuilder.prototype._getLineNumberEl = function(content, side) {
let row = content;
while (row && !row.classList.contains('diff-row')) row = row.parentElement;
return row ? row.querySelector('.lineNum.' + side) : null;
};
window.GrDiffBuilder = GrDiffBuilder;
})(window, GrDiffGroup, GrDiffLine);