IntelliJ Platform SDK DevGuide

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Settings Tutorial

Introduction

As discussed in the Settings Guide, plugins can add Settings to IntelliJ Platform-based IDEs. The IDE displays the Settings in response to a user choosing Settings/Preferences. Custom Settings are displayed and function just like those native to the IDE.

Overview of a Custom Settings Implementation

Using the SDK code sample settings, this tutorial illustrates the steps to create custom Application-level Settings. Many IntelliJ Platform Settings implementations use fewer classes, but the settings code sample factors the functionality into three classes for clarity:

  • The AppSettingsConfigurable is analogous to a Controller in the MVC model - it interacts with the other two Settings classes and the IntelliJ Platform,
  • The AppSettingsState is like a Model because it stores the Settings persistently,
  • The AppSettingsComponent is similar to a View because it displays and captures edits to the values of the Settings.

The structure of the implementation is the same for Project Settings, but there are minor differences in the Configurable implementation and Extension Point (EP) declaration.

The AppSettingsState Class

The AppSettingsState class persistently stores the custom Settings. It is based on the IntelliJ Platform Persistence Model.

Declaring AppSettingsState

Given a Light Service is not used, the persistent data class must be declared as a Service EP in the plugin.xml file. If these were Project Settings, the com.intellij.projectService EP would be used. However, because these are Application Settings, the com.intellij.applicationService EP is used with the FQN of the implementation class:

<extensions defaultExtensionNs="com.intellij"> <applicationService serviceImplementation="org.intellij.sdk.settings.AppSettingsState"/> </extensions>

Creating the AppSettingState Implementation

As discussed in Implementing the PersistentStateComponent Interface, AppSettingsState uses the pattern of implementing PersistentStateComponent itself:

// Copyright 2000-2020 JetBrains s.r.o. and other contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file. package org.intellij.sdk.settings; import com.intellij.openapi.components.PersistentStateComponent; import com.intellij.openapi.components.ServiceManager; import com.intellij.openapi.components.State; import com.intellij.openapi.components.Storage; import com.intellij.util.xmlb.XmlSerializerUtil; import org.jetbrains.annotations.NotNull; import org.jetbrains.annotations.Nullable; /** * Supports storing the application settings in a persistent way. * The {@link State} and {@link Storage} annotations define the name of the data and the file name where * these persistent application settings are stored. */ @State( name = "org.intellij.sdk.settings.AppSettingsState", storages = {@Storage("SdkSettingsPlugin.xml")} ) public class AppSettingsState implements PersistentStateComponent<AppSettingsState> { public String userId = "John Q. Public"; public boolean ideaStatus = false; public static AppSettingsState getInstance() { return ServiceManager.getService(AppSettingsState.class); } @Nullable @Override public AppSettingsState getState() { return this; } @Override public void loadState(@NotNull AppSettingsState state) { XmlSerializerUtil.copyBean(state, this); } }

Storage Annotation

The @State annotation, located just above the class declaration, defines the data storage location. For AppSettingsState, the data name parameter is the FQN of the class. Using FQN is a best practice to follow, and is required if custom data gets stored in the standard project or workspace files.

The storages parameter utilizes the @Storage annotation to define a custom file name for the AppSettingsState data. In this case, the file is located in the options directory of the configuration directory for the IDE.

Persistent Data Fields

The AppSettingState implementation has two public fields: a String and a boolean. Conceptually these fields hold the name of a user, and whether that person is an IntelliJ IDEA user, respectively. See Implementing the State Class for more information about how PersistentStateComponent serializes public fields.

AppSettingState Methods

The fields are so limited and straightforward for this class that encapsulation is not used for simplicity. All that’s needed for functionality is to override the two methods called by the IntelliJ Platform when a new component state is loaded (PersistentStateComponent.loadState()), and when a state is saved (PersistentStateComponent.getState()). See PersistentStateComponent for more information about these methods.

One static convenience method has been added - AppSettingState.getInstance() - which allows AppSettingsConfigurable to easily acquire a reference to AppSettingState.

The AppSettingsComponent Class

The role of the AppSettingsComponent is to provide a JPanel for the custom Settings to the IDE Settings Dialog. The AppSettingsComponent has-a JPanel, and is responsible for its lifetime. The AppSettingsComponent is instantiated by AppSettingsConfigurable.

Creating the AppSettingsComponent Implementation

The AppSettingsComponent defines a JPanel containing a JBTextField and a JBCheckBox to hold and display the data that maps to the data fields of AppSettingsState:

// Copyright 2000-2020 JetBrains s.r.o. and other contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file. package org.intellij.sdk.settings; import com.intellij.ui.components.JBCheckBox; import com.intellij.ui.components.JBLabel; import com.intellij.ui.components.JBTextField; import com.intellij.util.ui.FormBuilder; import org.jetbrains.annotations.NotNull; import javax.swing.*; /** * Supports creating and managing a {@link JPanel} for the Settings Dialog. */ public class AppSettingsComponent { private final JPanel myMainPanel; private final JBTextField myUserNameText = new JBTextField(); private final JBCheckBox myIdeaUserStatus = new JBCheckBox("Do you use IntelliJ IDEA? "); public AppSettingsComponent() { myMainPanel = FormBuilder.createFormBuilder() .addLabeledComponent(new JBLabel("Enter user name: "), myUserNameText, 1, false) .addComponent(myIdeaUserStatus, 1) .addComponentFillVertically(new JPanel(), 0) .getPanel(); } public JPanel getPanel() { return myMainPanel; } public JComponent getPreferredFocusedComponent() { return myUserNameText; } @NotNull public String getUserNameText() { return myUserNameText.getText(); } public void setUserNameText(@NotNull String newText) { myUserNameText.setText(newText); } public boolean getIdeaUserStatus() { return myIdeaUserStatus.isSelected(); } public void setIdeaUserStatus(boolean newStatus) { myIdeaUserStatus.setSelected(newStatus); } }

AppSettingsComponent Methods

The constructor builds the JPanel using the convenient FormBuilder, and saves a reference to the JPanel. The rest of the class are simple accessors and mutators to encapsulate the UI components used on the JPanel.

The AppSettingsConfigurable Class

The methods of AppSettingsConfigurable are called by the IntelliJ Platform, and AppSettingsConfigurable in turn interacts with AppSettingsComponent and AppSettingState.

Declaring the AppSettingsConfigurable

As described in Declaring Application Settings, the com.intellij.applicationConfigurable is used as the EP. An explanation of this declaration can be found in Declaring Application Settings:

<extensions defaultExtensionNs="com.intellij"> <applicationConfigurable parentId="tools" instance="org.intellij.sdk.settings.AppSettingsConfigurable" id="org.intellij.sdk.settings.AppSettingsConfigurable" displayName="SDK: Application Settings Example"/> </extensions>

Creating the AppSettingsConfigurable Implementation

The AppSettingsConfigurable class implements Configurable interface. The class has one field to hold a reference to the AppSettingsComponent.

// Copyright 2000-2020 JetBrains s.r.o. and other contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file. package org.intellij.sdk.settings; import com.intellij.openapi.options.Configurable; import org.jetbrains.annotations.Nls; import org.jetbrains.annotations.Nullable; import javax.swing.*; /** * Provides controller functionality for application settings. */ public class AppSettingsConfigurable implements Configurable { private AppSettingsComponent mySettingsComponent; // A default constructor with no arguments is required because this implementation // is registered as an applicationConfigurable EP @Nls(capitalization = Nls.Capitalization.Title) @Override public String getDisplayName() { return "SDK: Application Settings Example"; } @Override public JComponent getPreferredFocusedComponent() { return mySettingsComponent.getPreferredFocusedComponent(); } @Nullable @Override public JComponent createComponent() { mySettingsComponent = new AppSettingsComponent(); return mySettingsComponent.getPanel(); } @Override public boolean isModified() { AppSettingsState settings = AppSettingsState.getInstance(); boolean modified = !mySettingsComponent.getUserNameText().equals(settings.userId); modified |= mySettingsComponent.getIdeaUserStatus() != settings.ideaStatus; return modified; } @Override public void apply() { AppSettingsState settings = AppSettingsState.getInstance(); settings.userId = mySettingsComponent.getUserNameText(); settings.ideaStatus = mySettingsComponent.getIdeaUserStatus(); } @Override public void reset() { AppSettingsState settings = AppSettingsState.getInstance(); mySettingsComponent.setUserNameText(settings.userId); mySettingsComponent.setIdeaUserStatus(settings.ideaStatus); } @Override public void disposeUIResources() { mySettingsComponent = null; } }

AppSettingsConfigurable Methods

All the methods in this class are overrides of the methods in the Configurable interface. Readers are encouraged to review the Javadoc comments for the Configurable methods. Also review notes about IntelliJ Platform Interactions with Configurable methods.

Testing the Custom Settings Plugin

After performing the steps described above, compile and run the plugin in a Development Instance to see the custom Settings available in the Settings Dialog. Open the IDE Settings by selecting Settings/Preferences | Tools | SDK: Application Settings Example. The settings are preloaded with the default values:

"Settings Defaults"

Now edit the settings values to “John Doe” and click the checkbox. Click on the OK button to close the Settings dialog and save the changes. Exit the Development Instance.

Open the file SdkSettingsPlugin.xml to see the Settings persistently stored. In this demonstration the file resides in code_samples/settings/build/idea-sandbox/config/options/, but see IDE Development Instances for the general Development Instance case, or Default IDE directories if you are testing the settings plugin directly in an IDE.

"Persisted Settings"

Last modified: 21 September 2020