Skip to main content

Listening for Window Resize events with Prototype

Recently, I came across an issue I had with full-screen (more specifically, full-viewport) canvas drawing. It all worked fine, except that the canvas dimensions must be specified in pixels, as opposed to percentages. This means you can't just set the canvas' width and height to "100%" and be done with it...

The dimensions were automatically set when the page loaded, but if the user resized the browser window after that, the canvas would stay the same size, and would be either too big or too small. Thus, the canvas must be resized every time the browser window is resized.

Prototype makes all of this easy. All that's necessary is to attach a listener to the onresize event of the window object, and then use document.viewport.getDimensions() to determine the new width and height.

Here's some sample code:

Event.observe(window, "resize", function() {
    var width = document.viewport.getWidth();
    var height = document.viewport.getHeight();
    var dims = document.viewport.getDimensions(); // dims.width and dims.height
});

Alternatively, you can use document.viewport.getWidth() or document.viewport.getHeight() instead of document.viewport.getDimensions().

This code works in all major browsers, IE included.

Comments

  1. Liztek UD-3800 USB 3.0 Universal Docking Station Dual Monitor(VGA, HDMI and DVI to 2048x1152, Gigabit Ethernet, 2 USB 3.0 Ports w/ Tablets/Smartphones Charging Function, 4 USB 2.0 Ports, Audio for Headset and Microphone , 12V/2A AC Power Adapter) Perfect for Laptop, Ultrabook and PCs.Buy Now at amazon.com
    Liztek Universal Docking Station

    ReplyDelete

Post a Comment

Popular posts from this blog

Linux on XPS 15 9550/9560 with TB16 Dock [Update:3/29]

Finally got a laptop to replace my fat tower at work - Dell XPS 15 9560. I was allowed to choose which one I wanted and chose the XPS for its Linux support since Dell ships developer edition XPS's running Ubuntu so I figured Linux support would be better than other manufacturers. At first they got me the model with the 4K screen but my monitors are 2K and multi-dpi support in Linux is virtually non-existent and even hi-dpi support on its own is pretty terrible. So I got it exchanged for the model with the regular 1080p screen (which happened to also be the updated 9560 model), which works much better. I'm very glad to report that pretty much everything works, including the TB16 desktop dock, with just a bit of settings tweaking. This post is to help anybody considering getting this setup or looking for help getting things working. For now, I am running Kubuntu 16.04 with KDE Neon installed.

List of things I explicitly tested and work:
WiFi, BluetoothThunderbolt charging from T…

JComboBox with Disabled Items

Recently, I was working on a project in Java and needed to have a combo box, but with certain items in the list disabled (e.g. gray and non-selectable). At first, I simply set a custom renderer for the combo box which checked if the item was disabled. That, however, did not prevent the items from being selected. Thus, I set about to find a viable solution. There are plenty of solutions out there, but none seemed to work exactly the way I wanted. In the end, I ended up subclassing JComboBox to provide the functionality of disabling individual items. Here is my result, in under 100 lines:

import java.awt.Component; import java.util.ArrayList; import javax.swing.JComboBox; import javax.swing.JList; import javax.swing.plaf.basic.BasicComboBoxRenderer; public class PartialDisableComboBox extends JComboBox { private static final long serialVersionUID = -1690671707274328126L; private ArrayList<boolean> itemsState = new ArrayList<boolean>(); public PartialDisableComboBox()…

Broadcom Bluetooth Driver: Installer or Virus??

My primary computer at the moment is an HP dv6 laptop (with Broadcom 2070 Bluetooth chip). Upon getting my laptop, I immediately wiped the hard drive and slapped on a fresh copy of Windows 7. Installed the drivers from HP, and everything was rolling along nicely...

Fast-forward 4 months... Now I'm having some issues with Bluetooth communication between my phone (Android) and my laptop. So I reinstall the Bluetooth driver... The installation took a long time, but eventually errored-out, and quit. Of course, I had left the computer unattended during this, and came back to an almost-empty hard drive (!!!!). Restored for backup, some minor data loss, no problem... I thought I had snagged a virus in the download (even though it was direct from HP's site). Redownload, scan with multiple scanners, run it ....... SAME RESULT!!! Giving up on the official installer, I just took the drivers that the installer unpacked, and manually installed them... That didn't solve my original prob…