GridPanel BufferRender Plugin

gc.getView().bufferedRenderer.scrollTo(0, false);
gc.plugins to get the plugin

 

grid.getView().bufferedRenderer.scrollTo(0, false, function () {
    grid.getStore().reload({ params: { json: jsonString} });
});

gc.getView().bufferedRenderer.viewSize

//This large size is just a big number we can assume so that the DOM will be completely loaded and you can give it to print.Its a workaround. Again you can resize the view by setting it to small number.
bufferedRendererPlugin.setViewSize(115); 

// Set view size to match store content:
this.bufferedRenderer.setViewSize(this.getStore().getCount());
// Refresh view, so that everything is rendered:
this.bufferedRenderer.refreshView(0);
// refreshView does not revert the node container's "translate" setting after the viewSize was changed to be equal or greater than the store count, so we have to enforce it manually:
this.getView().getEl().down(this.getView().getNodeContainerSelector()).translate(0,0,0);