1 // To make sure we can uniquely identify each screenshot tab, add an id as a 2 // query param to the url that displays the screenshot. 3 var id = 100; 4 5 function takeScreenshot() { 6 chrome.tabs.captureVisibleTab(null, function(img) { 7 var screenshotUrl = img; 8 var viewTabUrl = [chrome.extension.getURL('screenshot.html'), 9 '?id=', id++].join(''); 10 11 chrome.tabs.create({url: viewTabUrl}, function(tab) { 12 var targetId = tab.id; 13 14 var addSnapshotImageToTab = function(tabId, changedProps) { 15 // We are waiting for the tab we opened to finish loading. 16 // Check that the the tab's id matches the tab we opened, 17 // and that the tab is done loading. 18 if (tabId != targetId || changedProps.status != "complete") 19 return; 20 21 // Passing the above test means this is the event we were waiting for. 22 // There is nothing we need to do for future onUpdated events, so we 23 // use removeListner to stop geting called when onUpdated events fire. 24 chrome.tabs.onUpdated.removeListener(addSnapshotImageToTab); 25 26 // Look through all views to find the window which will display 27 // the screenshot. The url of the tab which will display the 28 // screenshot includes a query parameter with a unique id, which 29 // ensures that exactly one view will have the matching URL. 30 var views = chrome.extension.getViews(); 31 for (var i = 0; i < views.length; i++) { 32 var view = views[i]; 33 if (view.location.href == viewTabUrl) { 34 view.setScreenshotUrl(screenshotUrl); 35 break; 36 } 37 } 38 }; 39 chrome.tabs.onUpdated.addListener(addSnapshotImageToTab); 40 41 }); 42 }); 43 } 44 45 // Listen for a click on the camera icon. On that click, take a screenshot. 46 chrome.browserAction.onClicked.addListener(function(tab) { 47 takeScreenshot(); 48 }); 49