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| <html> | |
| <head> | |
| <meta charset="utf-8"> | |
| <title>CodeMirror: B-Tree visualization</title> | |
| <link rel="stylesheet" href="../lib/codemirror.css"> | |
| <script src="../lib/codemirror.js"></script> | |
| <link rel="stylesheet" href="../doc/docs.css"> | |
| <style type="text/css"> | |
| .lineblock { display: inline-block; margin: 1px; height: 5px; } | |
| .CodeMirror {border: 1px solid #aaa; height: 400px} | |
| </style> | |
| </head> | |
| <body> | |
| <h1>CodeMirror: B-Tree visualization</h1> | |
| <p>Shows a visual representation of the b-tree that CodeMirror | |
| uses to store its document. See | |
| the <a href="http://marijnhaverbeke.nl/blog/codemirror-line-tree.html">corresponding | |
| blog post</a> for a description of this format. The gray blocks | |
| under each leaf show the lines it holds (with their width | |
| representing the line height). Add and remove content to see how | |
| the nodes are split and merged to keep the tree balanced.</p> | |
| <div style="position: relative"> | |
| <div style="width: 60%; display: inline-block; vertical-align: top"> | |
| <form><textarea id="code" name="code">type here, see a summary of the document b-tree to the right</textarea></form> | |
| </div> | |
| <div style="display: inline-block; height: 402px; overflow-y: auto" id="output"></div> | |
| </div> | |
| <script id="me"> | |
| var editor = CodeMirror.fromTextArea(document.getElementById("code"), { | |
| lineNumbers: true, | |
| lineWrapping: true | |
| }); | |
| var updateTimeout; | |
| editor.on("change", function(cm) { | |
| clearTimeout(updateTimeout); | |
| updateTimeout = setTimeout(updateVisual, 200); | |
| }); | |
| updateVisual(); | |
| function updateVisual() { | |
| var out = document.getElementById("output"); | |
| out.innerHTML = ""; | |
| function drawTree(out, node) { | |
| if (node.lines) { | |
| out.appendChild(document.createElement("div")).innerHTML = | |
| "<b>leaf</b>: " + node.lines.length + " lines, " + Math.round(node.height) + " px"; | |
| var lines = out.appendChild(document.createElement("div")); | |
| lines.style.lineHeight = "6px"; lines.style.marginLeft = "10px"; | |
| for (var i = 0; i < node.lines.length; ++i) { | |
| var line = node.lines[i], lineElt = lines.appendChild(document.createElement("div")); | |
| lineElt.className = "lineblock"; | |
| var gray = Math.min(line.text.length * 3, 230), col = gray.toString(16); | |
| if (col.length == 1) col = "0" + col; | |
| lineElt.style.background = "#" + col + col + col; | |
| console.log(line.height, line); | |
| lineElt.style.width = Math.max(Math.round(line.height / 3), 1) + "px"; | |
| } | |
| } else { | |
| out.appendChild(document.createElement("div")).innerHTML = | |
| "<b>node</b>: " + node.size + " lines, " + Math.round(node.height) + " px"; | |
| var sub = out.appendChild(document.createElement("div")); | |
| sub.style.paddingLeft = "20px"; | |
| for (var i = 0; i < node.children.length; ++i) | |
| drawTree(sub, node.children[i]); | |
| } | |
| } | |
| drawTree(out, editor.getDoc()); | |
| } | |
| function fillEditor() { | |
| var sc = document.getElementById("me"); | |
| var doc = (sc.textContent || sc.innerText || sc.innerHTML).replace(/^\s*/, "") + "\n"; | |
| doc += doc; doc += doc; doc += doc; doc += doc; doc += doc; doc += doc; | |
| editor.setValue(doc); | |
| } | |
| </script> | |
| <p><button onclick="fillEditor()">Add a lot of content</button></p> | |
| </body> | |
| </html> | |