panning and zooming

Question

I am creating an application where i need to zoomin/zoomout a document on finger pinch. I used Viewport.js for the same but there is a small limitation with that. When the document is redrawn its redrawn only from top-left. I need the effect to be shown in atleast 2 directions. Also i need the code in javascript.

else if (evt.touches != null && evt.touches.length == 2) {
                //when touched with 2 fingers, i.e for zooming
                //Zooming only if the page is opened in 'view' mode
                if (pageScope.mode == 'view') {
                    var touchx1 = evt.touches[0].pageX;
                    var touchy1 = evt.touches[0].pageY;
                    var touchx2 = evt.touches[1].pageX;
                    var touchy2 = evt.touches[1].pageY;
                    var distXY = Math.sqrt(Math.pow((touchx2 - touchx1), 2) + Math.pow((touchy2 - touchy1), 2));
                    if (distXY > dist) {
                        viewport.zoomIn();
                    } else if (distXY < dist) {
                        viewport.zoomOut();
                    }
                    viewport.draw();
                    dist = distXY;
                }
            }

The attached code detects 2 fingers touch and executes the zoom accordingly. Can anyone suggest how this can be achieved?

Why do you need to do anything? Most touch devices support zooming natively. — RobG, Jul 05 '12 at 08:38
my application need to have that effect. a document loaded in my app wont have that effect by default. I will have to implement it. — Khush, Jul 05 '12 at 08:48

panning and zooming

0 Answers0