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How to compute chars width? 2 ways: DOM & Canvas
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| <!DOCTYPE html> | |
| <html> | |
| <head lang="en"> | |
| <meta charset="UTF-8"> | |
| <title></title> | |
| </head> | |
| <body> | |
| <script> | |
| var getTextWidthDOM = function(text, fontStyle) { | |
| var node = getTextWidthDOM.node, | |
| width; | |
| if ( ! node) { | |
| node = getTextWidthDOM.node = document.createElement('span'); | |
| node.style.whiteSpace = 'nowrap'; | |
| node.style.visibility = 'hidden'; | |
| node.style.position = 'absolute'; | |
| node.style.height = 'auto'; | |
| node.style.width = 'auto'; | |
| } | |
| document.body.appendChild(node); | |
| node.style.font = fontStyle; | |
| node.innerHTML = text; | |
| width = node.offsetWidth; | |
| document.body.removeChild(node); | |
| return width; | |
| }; | |
| var getTextWidthCanvas = function(text, fontStyle) { | |
| getTextWidthCanvas.canvas || (getTextWidthCanvas.canvas = document.createElement("canvas")); | |
| var context = getTextWidthCanvas.canvas.getContext("2d"); | |
| context.font = fontStyle; | |
| return context.measureText(text).width; | |
| }; | |
| var CHARS_RANGES = [ | |
| [ 0x0400, 0x04FF ], // Cyrillic | |
| [ 0x001F, 0x007F ] // Latin | |
| ], | |
| FONT_STYLE = '13px arial', | |
| charsWidth = {}; | |
| CHARS_RANGES.forEach(function(range) { | |
| for (var charCode = range[0], char; charCode <= range[1]; charCode++) { | |
| char = String.fromCharCode(charCode); | |
| charsWidth[char] = [ | |
| getTextWidthCanvas(char, FONT_STYLE), | |
| getTextWidthDOM(char, FONT_STYLE) | |
| ]; | |
| } | |
| }); | |
| console.log(charsWidth); | |
| </script> | |
| </body> | |
| </html> |
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https://developer.mozilla.org/en-US/docs/Web/API/TextMetrics