From e47cbe1286a2143b0f8078a683e96edea0ed967b Mon Sep 17 00:00:00 2001
From: Bart Riepe <bart@serial-experiments.com>
Date: Thu, 19 Oct 2023 14:06:06 +0900
Subject: [PATCH] feat: add summary element and fold expansion/folding (fixes
 #22, #21)

---
 examples/src/index.tsx       | 23 ++++++++-
 src/compute-hidden-blocks.ts |  2 +-
 src/expand.tsx               |  3 ++
 src/fold.tsx                 |  3 ++
 src/index.tsx                | 98 ++++++++++++++++++++++++------------
 src/styles.ts                | 38 +++++++++++++-
 6 files changed, 132 insertions(+), 35 deletions(-)
 create mode 100644 src/expand.tsx
 create mode 100644 src/fold.tsx

diff --git a/examples/src/index.tsx b/examples/src/index.tsx
index 4a8d3e2..e825169 100644
--- a/examples/src/index.tsx
+++ b/examples/src/index.tsx
@@ -18,6 +18,7 @@ interface ExampleState {
   language?: string;
   theme: 'dark' | 'light';
   enableSyntaxHighlighting?: boolean;
+  columnHeaders: boolean;
   compareMethod?: DiffMethod;
   customGutter?: boolean;
 }
@@ -31,6 +32,7 @@ class Example extends Component<{}, ExampleState> {
       highlightLine: [],
       theme: 'dark',
       splitView: true,
+      columnHeaders: true,
       customGutter: true,
       enableSyntaxHighlighting: true,
       compareMethod: DiffMethod.CHARS
@@ -145,6 +147,22 @@ class Example extends Component<{}, ExampleState> {
               </label>
               <span>Syntax highlighting</span>
             </div>
+            <div>
+              <label className={'switch'}>
+                <input
+                  type="checkbox"
+                  checked={this.state.columnHeaders}
+                  onChange={() => {
+                    this.setState({
+                      columnHeaders:
+                        !this.state.columnHeaders,
+                    });
+                  }}
+                />
+                <span className="slider round"></span>
+              </label>
+              <span>Column Headers</span>
+            </div>
             <div>
               <label className={'switch'}>
                 <input
@@ -225,8 +243,9 @@ class Example extends Component<{}, ExampleState> {
                 : undefined
             }
             useDarkTheme={this.state.theme === 'dark'}
-            leftTitle={`${this.state.compareMethod === DiffMethod.JSON ? 'package.json' : 'webpack.config.js'} master@2178133 - pushed 2 hours ago.`}
-            rightTitle={`${this.state.compareMethod === DiffMethod.JSON ? 'package.json' : 'webpack.config.js'} master@64207ee - pushed 13 hours ago.`}
+            summary={this.state.compareMethod === DiffMethod.JSON ? 'package.json' : 'webpack.config.js'}
+            leftTitle={this.state.columnHeaders ? `master@2178133 - pushed 2 hours ago.` : undefined}
+            rightTitle={this.state.columnHeaders ? `master@64207ee - pushed 13 hours ago.` : undefined}
           />
         </div>
         <footer>
diff --git a/src/compute-hidden-blocks.ts b/src/compute-hidden-blocks.ts
index 7eae629..ec92870 100644
--- a/src/compute-hidden-blocks.ts
+++ b/src/compute-hidden-blocks.ts
@@ -1,7 +1,7 @@
 import {DiffType, LineInformation} from "./compute-lines";
 import {ReactElement} from "react";
 
-interface Block {
+export interface Block {
   index: number
   startLine: number
   endLine: number
diff --git a/src/expand.tsx b/src/expand.tsx
new file mode 100644
index 0000000..d5b4f2b
--- /dev/null
+++ b/src/expand.tsx
@@ -0,0 +1,3 @@
+export function Expand() {
+  return <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="16" height="16"><path d="m8.177.677 2.896 2.896a.25.25 0 0 1-.177.427H8.75v1.25a.75.75 0 0 1-1.5 0V4H5.104a.25.25 0 0 1-.177-.427L7.823.677a.25.25 0 0 1 .354 0ZM7.25 10.75a.75.75 0 0 1 1.5 0V12h2.146a.25.25 0 0 1 .177.427l-2.896 2.896a.25.25 0 0 1-.354 0l-2.896-2.896A.25.25 0 0 1 5.104 12H7.25v-1.25Zm-5-2a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5ZM6 8a.75.75 0 0 1-.75.75h-.5a.75.75 0 0 1 0-1.5h.5A.75.75 0 0 1 6 8Zm2.25.75a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5ZM12 8a.75.75 0 0 1-.75.75h-.5a.75.75 0 0 1 0-1.5h.5A.75.75 0 0 1 12 8Zm2.25.75a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5Z"></path></svg>
+}
diff --git a/src/fold.tsx b/src/fold.tsx
new file mode 100644
index 0000000..c1c2da9
--- /dev/null
+++ b/src/fold.tsx
@@ -0,0 +1,3 @@
+export function Fold() {
+  return <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="16" height="16"><path d="M10.896 2H8.75V.75a.75.75 0 0 0-1.5 0V2H5.104a.25.25 0 0 0-.177.427l2.896 2.896a.25.25 0 0 0 .354 0l2.896-2.896A.25.25 0 0 0 10.896 2ZM8.75 15.25a.75.75 0 0 1-1.5 0V14H5.104a.25.25 0 0 1-.177-.427l2.896-2.896a.25.25 0 0 1 .354 0l2.896 2.896a.25.25 0 0 1-.177.427H8.75v1.25Zm-6.5-6.5a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5ZM6 8a.75.75 0 0 1-.75.75h-.5a.75.75 0 0 1 0-1.5h.5A.75.75 0 0 1 6 8Zm2.25.75a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5ZM12 8a.75.75 0 0 1-.75.75h-.5a.75.75 0 0 1 0-1.5h.5A.75.75 0 0 1 12 8Zm2.25.75a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5Z"></path></svg>
+}
diff --git a/src/index.tsx b/src/index.tsx
index bfde278..1abc7c4 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1,12 +1,13 @@
 import * as React from 'react';
-import * as PropTypes from 'prop-types';
+import {ReactElement} from 'react';
 import cn from 'classnames';
 
 import {computeLineInformation, DiffInformation, DiffMethod, DiffType, LineInformation,} from './compute-lines';
 import computeStyles, {ReactDiffViewerStyles, ReactDiffViewerStylesOverride,} from './styles';
-import {ReactElement} from "react";
-import {computeHiddenBlocks} from "./compute-hidden-blocks";
+import {Block, computeHiddenBlocks} from "./compute-hidden-blocks";
 import IntrinsicElements = React.JSX.IntrinsicElements;
+import {Expand} from "./expand";
+import {Fold} from "./fold";
 
 const m = require('memoize-one');
 
@@ -69,6 +70,10 @@ export interface ReactDiffViewerProps {
   styles?: ReactDiffViewerStylesOverride;
   // Use dark theme.
   useDarkTheme?: boolean;
+  /**
+   * Used to describe the thing being diffed
+   */
+  summary?: string | ReactElement;
   // Title for left column
   leftTitle?: string | ReactElement;
   // Title for left column
@@ -519,7 +524,7 @@ class DiffViewer extends React.Component<
   /**
    * Generates the entire diff view.
    */
-  private renderDiff = (): {leftLines: ReactElement[], rightLines: ReactElement[]} => {
+  private renderDiff = (): {leftLines: ReactElement[], rightLines: ReactElement[], lineInformation: LineInformation[], blocks: Block[] } => {
     const {
       oldValue,
       newValue,
@@ -577,7 +582,7 @@ class DiffViewer extends React.Component<
         rightLines.push(...right)
       },
     );
-    return {leftLines, rightLines};
+    return {leftLines, rightLines, lineInformation, blocks};
   };
 
   public render = (): ReactElement => {
@@ -600,36 +605,67 @@ class DiffViewer extends React.Component<
 
     this.styles = this.computeStyles(this.props.styles, useDarkTheme, nonce);
     const nodes = this.renderDiff();
-    const colSpanOnSplitView = hideLineNumbers ? 2 : 3;
-    const colSpanOnInlineView = hideLineNumbers ? 2 : 4;
-    let columnExtension = this.props.renderGutter ? 1 : 0;
-
-    console.log(nodes.rightLines)
+    let deletions = 0, additions = 0
+    nodes.lineInformation.forEach((l) => {
+      if (l.left.type === DiffType.ADDED) {
+        additions++
+      }
+      if (l.right.type === DiffType.ADDED) {
+        additions++
+      }
+      if (l.left.type === DiffType.REMOVED) {
+        deletions++
+      }
+      if (l.right.type === DiffType.REMOVED) {
+        deletions++
+      }
+    })
+    const totalChanges = deletions + additions
+
+    const percentageAddition = Math.round((additions / totalChanges) * 100)
+    const blocks: ReactElement[] = []
+    for(let i = 0; i < 5; i++) {
+      if (percentageAddition > i * 20) {
+        blocks.push(<span key={i} className={cn(this.styles.block, this.styles.blockAddition)} />)
+      } else {
+        blocks.push(<span key={i} className={cn(this.styles.block, this.styles.blockDeletion)} />)
+      }
+    }
+    const allExpanded = this.state.expandedBlocks.length === nodes.blocks.length
 
     return (
-      <div
-        className={cn(this.styles.diffContainer, {
-          [this.styles.splitView]: splitView,
-        })}
-      >
-        <div className={this.styles.column} role={'table'} title={`Diff information for ${leftTitle}`}>
-          <div
-            className={cn(this.styles.titleBlock, this.styles.column)}
-            role={'columnheader'}
-          >
-            <pre className={this.styles.contentText}>{leftTitle}</pre>
-          </div>
-          {nodes.leftLines}
+      <div>
+        <div className={this.styles.summary} role={'banner'}>
+          <a style={{ cursor: 'pointer'}} onClick={() => {
+            this.setState({
+              expandedBlocks: allExpanded ? [] : nodes.blocks.map(b => b.index)
+            })
+          }}>{allExpanded ? <Fold /> : <Expand />}</a> {totalChanges} <div style={{ display: 'flex', gap: '1px'}}>{blocks}</div> {this.props.summary ? <span>{this.props.summary}</span> : null}
         </div>
-        {nodes.rightLines.length > 0 ? <div className={this.styles.column} role={'table'} title={`Diff information for ${rightTitle}`}>
-          <div
-            className={cn(this.styles.titleBlock, this.styles.column)}
-            role={'columnheader'}
-          >
-            <pre className={this.styles.contentText}>{rightTitle}</pre>
+        <div
+          className={cn(this.styles.diffContainer, {
+            [this.styles.splitView]: splitView,
+          })}
+        >
+          <div className={this.styles.column} role={'table'} title={`Diff information for ${leftTitle}`}>
+            {leftTitle ? <div
+              className={cn(this.styles.titleBlock, this.styles.column)}
+              role={'columnheader'}
+            >
+              <pre className={this.styles.contentText}>{leftTitle}</pre>
+            </div> : null }
+            {nodes.leftLines}
           </div>
-          {nodes.rightLines}
-        </div> : null}
+          {nodes.rightLines.length > 0 ? <div className={this.styles.column} role={'table'} title={`Diff information for ${rightTitle}`}>
+            {rightTitle ? <div
+              className={cn(this.styles.titleBlock, this.styles.column)}
+              role={'columnheader'}
+            >
+              <pre className={this.styles.contentText}>{rightTitle}</pre>
+            </div> : null}
+            {nodes.rightLines}
+          </div> : null}
+        </div>
       </div>
     );
   };
diff --git a/src/styles.ts b/src/styles.ts
index 75ee590..45ee944 100644
--- a/src/styles.ts
+++ b/src/styles.ts
@@ -18,6 +18,7 @@ export interface ReactDiffViewerStyles {
   wordAdded?: string;
   wordRemoved?: string;
   codeFoldGutter?: string;
+  summary?: string;
   codeFoldContentContainer?: string;
   emptyGutter?: string;
   emptyLine?: string;
@@ -151,7 +152,7 @@ export default (
         removedGutterColor: '#8c8c8c',
         codeFoldContentColor: '#656a8b',
         diffViewerTitleBackground: '#2f323e',
-        diffViewerTitleColor: '#555a7b',
+        diffViewerTitleColor: '#757a9b',
         diffViewerTitleBorderColor: '#353846',
       },
       ...(overrideVariables.dark || {}),
@@ -172,6 +173,17 @@ export default (
     label: 'split-view',
   });
 
+  const summary = css({
+    background: variables.diffViewerTitleBackground,
+    color: variables.diffViewerTitleColor,
+    padding: '0.5em 1em',
+    display: 'flex',
+    alignItems: 'center',
+    gap: '0.5em',
+    fontFamily: "monospace",
+    fill: variables.diffViewerTitleColor,
+  })
+
   const diffContainer = css({
     width: '100%',
     minWidth: '1000px',
@@ -261,11 +273,13 @@ export default (
 
   const wordAdded = css({
     background: variables.wordAddedBackground,
+    textDecoration: 'none',
     label: 'word-added',
   });
 
   const wordRemoved = css({
     background: variables.wordRemovedBackground,
+    textDecoration: 'none',
     label: 'word-removed',
   });
 
@@ -284,6 +298,24 @@ export default (
     label: 'code-fold-content',
   });
 
+  const block = css({
+    display: 'block',
+    width: '10px',
+    height: '10px',
+    backgroundColor: '#ddd',
+    borderWidth: '1px',
+    borderStyle: 'solid',
+    borderColor: variables.diffViewerTitleBorderColor
+  });
+
+  const blockAddition = css({
+    backgroundColor: variables.wordAddedBackground
+  })
+
+  const blockDeletion = css({
+    backgroundColor: variables.wordRemovedBackground
+  })
+
   const codeFold = css({
     backgroundColor: variables.codeFoldBackground,
     height: 40,
@@ -404,6 +436,10 @@ export default (
     lineContent,
     wordDiff,
     wordAdded,
+    summary,
+    block,
+    blockAddition,
+    blockDeletion,
     wordRemoved,
     codeFoldGutter,
     codeFoldContentContainer,