Perforce JViews Diagrammer Sample: Accessibility

Description

This sample shows how to implement various accessibily features when displaying a Perforce JViews Diagrammer.

How to Use the Sample

Accessibility means making software usable by people with certain common disabilities. Examples are the physical inability to move a mouse, low vision, or color blindness. This demonstration illustrates the features of JViews that support accessibility:
- Using the keyboard instead of the mouse
- Setting a high contrast mode to support people with low vision
- Selecting suitable colors for color blind people
In making your choice of colors, keep in mind that many people see colors in a different way. Indicate important information not only by different colors, but also by different shapes. To specify the color mode, use the submenu 'Color Mode' in the View menu. Available values and their meanings are as follows:
- Normal: This is how people with normal vision see the colors.
- Grayscale: Simulation of monochromatic vision. This variant of color blindness is rare
- Deutan: Simulation of deutan vision. People with deutan vision see the colors approximately in this way. Deutan vision and protan vision are both variants of red-green color blindness. Deutan and protan vision occur in 8% of all males, and 0.5% of all females.
In Deutan or Grayscale mode, certain nodes are not easy to distinguish. Therefore, it is recommended to encode information not only by using colors but also by using additional indicators such as node shapes. This makes it more easy for people with color vision deficiency to recognize the diagram. To style the nodes with different shapes, use the option 'Vary Shapes' in the View menu.
High Contrast mode helps people with low vision. To style the nodes with high contrast, use the option 'High Contrast' in the View menu.
Control the view by using the toolbar on the left of the window.
- Sets the view in Select mode. Select nodes and links by clicking on them.
- Zoom in.
- Zoom out.
- Zoom in on an area by selecting the area to be magnified.
- Set the zoom level back to 1:1.
- Fit to view: Make the entire image visible.
- Sets the view in Pan mode. Pan the view by dragging the image.
- Show the data model in a tree view.
- Show the data model in a table view.
- Show the overview of the diagram.
All interactions are also available through the keyboard.
Initially, there is no focus on the view, indicated by the label "No focus on view" in the upper-right corner. This means that the view does not react to the keyboard. Press the TAB key several times, or click into the view, until the label changes to "Key:0x----(x)-------". Now the view has the focus and reacts to keys.

These are the key actions:

Tab	Select the next graphic object, or the next GUI element. You can also use Tab to select all combination boxes and buttons in the demonstration.
Shift+Tab	Select the previous graphic object.
F	Select the next graphic object.
B	Select the previous graphic object.
A	Select all graphic objects.
Ctrl+A	Deselect all graphic objects.
Arrow keys	Scroll up, down, left, right
Ctrl+Arrow keys on the numeric keypad	Scroll up, down, left, right
Ctrl+F	Fit to view
Ctrl+5 on the numeric keypad	Fit to view
Ctrl+0	Set identity zoom
Ctrl+0 on the numeric keypad	Set identity zoom
Ctrl+Home	Set identity zoom
Ctrl+plus sign key (+)	Zoom in
Ctrl+plus sign key (+) on the numeric keypad	Zoom in
Ctrl+minus sign key (-)	Zoom out
Ctrl+minus sign key (-) on the numeric keypad	Zoom out
Ctrl+R	Rotate the view by 90 degree
F1	When a node is selected: Open the pop-up menu. Use the arrow keys to choose the pop-up menu option. Use the Enter key to finish the action, or the ESC key to cancel the action.
P	When a node is selected: Open the pop-up menu.
Del	When a node is selected: Delete the selected node.
Shift+Arrow keys	When a node is selected: Move the selected node.
Shift+Arrow keys on the numeric keypad	When a node is selected: Move the selected node.
E	When a subgraph is selected: Expand or collapse the selected subgraph.

How to Run the Sample as an Application

This sample can be run as an application. The installation directory contains an executable JAR file, diagrammer-accessibility.jar, that allows you to execute the sample with a double click from a file browser. Note that if you are using Internet Explorer, you can open the installation directory and execute the JAR file from the browser. This technique may not work in other Web browsers.

Alternatively, you can run the sample application from the command line. First check that the Ant utility is properly configured. If not, see the instructions on how to configure Ant for Perforce JViews.

Then, go to the installation directory of the sample and type:

ant run

Topics Covered

Load Perforce JViews Diagrammer project files.

Installation Directory

The Accessibility sample is installed here.

Classes Involved

Source Files

AccessibleDiagram
The entry point of the sample.