opera.extension.getScreenshot() and BrowserTab.getScreenshot()

By Opera Software

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Description:

Captures a screenshot of a page within a tab.

Parameters:

• callback: The callback function to execute. The callback function takes an ImageData object as its parameter, provided by the API.

Syntax:

void getScreenshot (<Function> callback)

Example:

<!--
  The configuration file ('config.xml').
-->
<?xml version='1.0' encoding='utf-8'?>
<widget xmlns="http://www.w3.org/ns/widgets">
    <feature name="opera:screenshot" required="false"/>
</widget>

//
// An injected script (e.g. includes/injected.js)
//

window.addEventListener('load', function() {
  // Check the Screenshot API is available
  if (opera.extension.getScreenshot) {
    opera.postError('Screenshot API found');

    // Callback function to replace page content with the screenshot
    function applyScreenshot(imageData) {
      opera.postError('Appending screenshot to current page...');

      // Create a blank canvas
      var canvas = document.createElement('canvas');
      canvas.width = imageData.width;
      canvas.height = imageData.height;

      // Write the screenshot image data to the canvas context
      var ctx = canvas.getContext('2d');
      ctx.putImageData(imageData, 0, 0);

      // Replace the page's content with the canvas
      var body = document.body;
      body.innerHTML = '';
      body.appendChild(canvas);

      opera.postError('Snapshot appended to current page.');
    }

    // Use the API's method to execute the callback function
    opera.extension.getScreenshot(applyScreenshot);
  } else {
    opera.postError('No Screenshot API found');
  }
}, false);

This article is licensed under a Creative Commons Attribution 3.0 Unported license.