Gecko:Printing API: Difference between revisions

Gecko:Printing API (view source)

1,235 bytes added , 5 January 2016

first draft of IDL addition and example

31

edits

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 Purpose of this document is to define a set of standards and API's to give web developers more control over printing output.
+== Example ==
+ window.startPrintJob(function (state) {
+ 	var canvas = document.createElement("canvas");
+ 	var ctx = canvas.getContext("2d");
+ 	if (!state.isPreview) {
+ 		canvas.width *= 5;
+ 		canvas.height *= 5;
+ 		ctx.scale(5, 5);
+ 	}
+ 	switch (state.currentPage) {
+ 		case 1:
+ 			ctx.drawText(0, 0, state.title);
+ 			break;
+ 		case 2:
+ 		case 3:
+ 			ctx.drawText(0, 0, "Page " + state.currentPage + " of " + state.totalPages);
+ 			break;
+ 		default:
+ 			return Promise.reject(Error("Invalid page number"));
+ 	}
+ 	return Promise.resolve(canvas);
+ }, 3, "Printing Example")
+ .then(function () {
+ 	console.log('Printing done');
+ }, function () {
+ 	console.error('Printing failed');
+ });
+== IDL addition ==
+ interface PrintPageHandler {
+ 	Promise getPageElement(PrintState state);
+ }
+ interface PrintState {
+ 	readonly attribute double totalPages;
+ 	readonly attribute DOMString title;
+ 	readonly attribute double currentPage;
+ 	readonly boolean isPreview: Boolean;
+ }
+ dictionary PrintOptions {
+ 	double totalPages	= 1;
+ 	DOMString title 	= "";
+ 	...
+ };
+ interface Printing {
+   Promise startPrintJob(PrintPageHandler handler,
+   			optional (unrestricted double or PrintOptions) options);
+ };
+ Window implements Printing;