tool_windows.md

title
Tool Windows

Tool Windows

Tool windows are child windows of IntelliJ IDEA used to display information. These windows generally have their own toolbars (referred to as tool window bars) along the outer edges of the main window containing one or more tool window buttons, which activate panels displayed on the left, bottom and right sides of the main IntelliJ IDEA toolwindow. For detailed information about tool windows, please see IntelliJ IDEA Web Help .

Each side contains two tool window groups, the primary and the secondary one, and only one toolwindow from each group can be active at a time.

Each toolwindow can show multiple tabs (or "contents", as they are called in the API). For example, the Run toolwindow displays a tab for each active run configuration, and the Changes toolwindow displays a fixed set of tabs depending on the version control system used in the project.

There are two main scenarios for the use of tool windows in a plugin. In the first scenario (used by the Ant and Commander plugins, for example), a toolwindow button is always visible, and the user can activate it and interact with the plugin functionality at any time. In the second scenario (used by the Analyze Dependencies action, for example), the toolwindow is created to show the results of a specific operation, and can be closed by the user after the operation is completed.

In the first scenario, the toolwindow is registered in plugin.xml using the <toolWindow> extension point. The extension point attributes specify all the data which is necessary to display the toolwindow button:

• The ID of the toolwindow (corresponds to the text displayed on the toolwindow button)

• The anchor, meaning the side of the screen on which the toolwindow is displayed ("left", "right" or "bottom")

• The "secondary" attribute, specifying whether the toolwindow is displayed in the primary or the secondary group

• The icon to display on the toolwindow button (13x13 pixels)

In addition to that, you specify the factory class - the name of a class implementing the ToolWindowFactory interface. When the user clicks on the toolwindow button, the createToolWindowContent() method of the factory class is called, and initializes the UI of the toolwindow. This procedure ensures that unused toolwindows don't cause any overhead in startup time or memory usage: if a user does not interact with the toolwindow of your plugin, no plugin code will be loaded or executed.

If the toolwindow of your plugin doesn't need to be displayed for all projects, you can also specify the conditionClass attribute - the qualified name of a class implementing the Condition<Project> interface (this can be the same class as the toolwindow factory implementation). If the condition returns false, the toolwindow will not be displayed. Note that the condition is evaluated only once when the project is loaded; if you'd like to show your and hide toolwindow dynamically while the user is working with the project, you need to use the second method for toolwindow registration.

The second method involves simply calling ToolWindowManager.registerToolWindow() from your plugin code. The method has multiple overloads that can be used depending on your task. If you use an overload that takes a component, the component becomes the first content (tab) displayed in the toolwindow.

Displaying the contents of many toolwindows requires access to the indexes. Because of that, toolwindows are normally disabled while building indices, unless you pass true as the value of canWorkInDumbMode to the registerToolWindow() function.

As mentioned previously, toolwindows can contain multiple tabs, or contents. To manage the contents of a toolwindow, you can call ToolWindow.getContentManager(). To add a tab (content), you first need to create it by calling ContentManager.getFactory().createContent(), and then to add it to the toolwindow using ContentManager.addContent().

You can control whether the user is allowed to close tabs either globally or on a per-tab basis. The former is done by passing the canCloseContents parameter to the registerToolWindow() function, or by specifying canCloseContents="true" in plugin.xml. If closing tabs is enabled in general, you can disable closing of specific tabs by calling Content.setCloseable(false).

How to Create a Tool Window?

The IntelliJ Platform provides the toolWindow extension point that you can use to create and configure your custom tool windows. This extension point is declared using the ToolWindowEP bean class.

To create a tool window, first declare an extension to the toolWindow extension point.

Creation of Plugin

To create a plugin that displays a custom tool window, perform the following steps:

1. In your plugin project, create a Java class that implements the ToolWindowFactoryinterface.
2. In this class, override the createToolWindowContent method. This method specifies the content for your tool window.
3. In the plugin configuration file plugin.xml, create the <extensions defaultExtensionNs="com.intellij">...</extensions> section.
4. To this section, add the <toolWindow> element, and for this element, set the following attributes declared in the ToolWindowEP bean class:
   • id (required): specifies the tool window caption.
   • anchor (required): specifies the tool window bar where the tool window button will be displayed. Possible values: "left", "right", "top", "bottom."
   • secondary (optional): when true, the tool window button will be shown on the lower part of the tool window bar. Default value is false.
   • factoryClass (required): specifies the Java class implementing the ToolWindowFactory interface (see Step 1).
   • icon (optional): specifies path to the icon that identifies the tool window, if any.
   • conditionClass (optional): specifies a Java class that implements the Condition interface. Using this class, you can define conditions to be met to display tool window button. In the Condition class, you should override the value method: if this method returns false, the tool window button is not displayed on tool window bar.

To clarify the above procedure, consider the following fragment of the plugin.xml file:

<extensions defaultExtensionNs="com.intellij">
    <toolWindow id="My Sample Tool Window" icon="/myPackage/icon.png" anchor="right" factoryClass="myPackage.MyToolWindowFactory"/>
</extensions>

Sample Plugin

To clarify how to develop plugins that create tool windows, consider the toolWindow sample plugin available in the code_samples directory of the SDK documentation. This plugin creates the Sample Calendar tool window that displays the system date, time and time zone.

To run toolWindow plugin

1. Start IntelliJ IDEA and open the tool_window project saved into the code_samples/tool_window directory.
2. Ensure that the project settings are valid for your environment. If necessary, modify the project settings.
   To view or modify the project settings, you can open the Project Structure.
3. Run the plugin by choosing the Run | Run on the main menu.
   If necessary, change the Run/Debug Configurations.

The plugin creates the Sample Calendar tool window. When opened, this tool window is similar to the following screen: