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• Launchpad Entry: compiz-mag

• Packages affected: compiz

Summary

Extend the beryl zoom plugin with cursor tracking functionality to provide a powerful magnifier for low vision users.

Release Note

Leveraging the compositing power of Compiz/Beryl we have created a next-generation magnifier for low-vision users. The new technology is both more responsive and more user friendly than previos tools.

Rationale

The current magnifier gnome-mag is slow and resource instensive. compiz can rovide much better magnification rendering via hardware accelleration.

Use Cases

Reading a news website

This (randomly chosen) news page has both text and pictures and a great deal of non-essential navigation items. A low-vision user wants to get a general overview at 2x zoom, but wants to read the text at 8x zoom. With compiz-mag she can switch between the two with a keystroke.

Creating a Research Paper

Multiple windows with multiple text sizes and colors can often be difficult for users to handle. The user should ultimately be able to comfortably see all information, write efficiently, and navigate efficiently. Ultimately this use case can be expanded with optional features shown below. For example when zoomed in to 3x a web page may still be using extremely small font whereas an application may be using "normal" font. The zooming should allow for window specific zooming

Assumptions

Design

• Fixed zoom factors - user-defined zoom levels that can be accessed with a hotkey
• Follow the text-entry cursor - using AT-SPI magic to get the location
• Jump to window that gains focus
• Mouse cursors - different size and colour options and a cross cursor
• Variable zoom factor - adjust using keys or mouse wheel
• Panning based on keyboard and/or mouse input

Optional features

• Different panning modes, including central cursor and edge-push (see gnome-mag)
• Sensitivity of zooming and panning should be configurable
• Define the zoom region to be part of or the whole screen
• Have zones where input combinations move you automatically to the zoomed spot (i.e. the menu bars)
• Multiple screen magnification with various levels of magnified windows on each.
• Allow Zoomtext Keyboard to work on Linux
• Carry your settings on a USB stick to be used on any computer
• Extend compiz-mag support for logins

Implementation

• Use internal Compiz information to fetch focus changes
• extend the compiz plugin to be controllable from external applications
• Direct cursor tracking with information from AT-SPI
• dbus for communication between apps

Test/Demo Plan

Outstanding Issues

Lack of input redirection in X.org limits the possibilities, specially for different panning modes and sensitivity. The mouse pointer has to be at the correct place at any given time, which means it has to be synchronized with the zoomed area to enable input.

BoF agenda and discussion

CategorySpec