// The image we want to view var imageblob; // Create an image from a canvas var canvas = document.createElement('canvas'); canvas.width = 600; canvas.height = 800; var context = canvas.getContext('2d'); context.font = '20pt Arial'; context.fillStyle = 'red'; context.fillText('Hello World', 100, 100); context.strokeStyle = 'blue'; context.lineWidth = 4; context.strokeRect(0, 0, 600, 800); canvas.toBlob(function(blob) { imageblob = blob; }, 'image/png'); document.getElementById('view').onclick = function() { var a = new MozActivity({ name: 'open', data: { type: 'image/png', blob: imageblob } }); a.onsuccess = function() { console.log('activity returns', JSON.stringify(a.result)); }; }; document.getElementById('viewsave').onclick = function() { var a = new MozActivity({ name: 'open', data: { type: 'image/png', blob: imageblob, allowSave: true, filename: 'downloads/uitests/helloworldhello.png' } }); a.onsuccess = function() { console.log('activity returns', JSON.stringify(a.result)); }; }; document.getElementById('viewError').onclick = function() { var a = new MozActivity({ name: 'open', data: { type: 'image/jpeg', blob: new Blob(['empty-image'], {'type': 'image/jpeg'}) } }); a.onsuccess = function() { console.log('activity returns', JSON.stringify(a.result)); }; };