KWin Rules

Overview

KWin allows the end-user to define rules to alter the behavior of an application's window attributes.

For example, when an application is started, it can be forced to always run on Virtual Desktop 2. Or a defect in an application can be worked-around to force the window above others.

Step-by-step examples are provided along with detailed information on using the KWin Rule Editor to specify Window Matching and Window Attributes.

Examples

A collection of examples is provided to convey the power of KWin window rules.

KWin Rule Editor

Invoking the KWin Rule Editor

There are several ways to invoke the KWin Rule Editor. Below are two:

• Right-click on the title-bar of any window, choose Configure Window Behavior ... and in the Configure window, select Window Rules or
• System Settings -> Window Behavior -> Window Rules

The main window is used to:

• Affect rules with New..., Modify... and Delete
• Share rules with others via Import and Export
• Ensure desired rule evaluation using Move Up and Move Down

Rule Evaluation

When an application starts (or the rules are modified), KWin evaluates the rules from the top of the list to the bottom. For all rules which match a window, the collective set of attributes are applied to the window and the window is displayed.

Should two or more matching rules set the same attribute, the setting found in the first rule in the list takes precedence.

Tip

You can tailor children windows for the application by placing the more restrictive rules first - see the Kopete and Kopete Chat Window example.

Rule Editor

The editor is composed of four tabs:

1. Window matching
2. Size & Position
3. Arrangement & Access
4. Appearance & Fixes

As the name implies, Window matching is used to specify criteria to match one or more windows. The other three tabs are used to alter the attributes of the matching windows.

Tip

Panels can also be affected.

Window Matching

Each window rule has user specified Window Matching criteria. KWin uses the criteria to determine whether the rule is applicable for an application.

Window Attributes

Along with Window Matching criteria, each window rule has a set of Window Attributes. The attributes override the corresponding application's settings and are applied before the window is displayed by KWin.