如何在IntelliJ IDEA插件中修改字体大小？含API选型咨询

Hey there! Let's tackle your IntelliJ IDEA plugin development questions one by one:

1. How to modify font sizes in your plugin? #

There are two key scenarios to cover: adjusting editor font sizes, and updating the IDE's global UI font sizes (like menus, toolbars, and dialog text). Here's how to handle both:

Editor Font Size #

To change the font size for text editors, use the EditorSettings and EditorSettingsExternalizable APIs to update the setting and make it persist:

// Get the currently active editor
Editor editor = FileEditorManager.getInstance(project).getSelectedTextEditor();
if (editor != null) {
    EditorSettings editorSettings = editor.getSettings();
    // Set your desired font size (e.g., 16)
    editorSettings.setFontSize(16);
    
    // Save the setting globally so it stays after IDE restarts
    EditorSettingsExternalizable globalEditorSettings = EditorSettingsExternalizable.getInstance();
    globalEditorSettings.setFontSize(16);
    globalEditorSettings.save();
}

Global UI Font Size #

For non-editor UI elements (menus, toolbars), target the UiSettings via ApplicationSettingsManager, then trigger a UI repaint to apply changes:

// Access application-level UI settings
ApplicationSettingsManager settingsManager = ApplicationSettingsManager.getInstance();
UiSettings uiSettings = settingsManager.getSettings(UiSettings.class);

// Set the new UI font size (e.g., 14)
uiSettings.setFontSize(14);

// Save the settings to disk
settingsManager.saveSettings(UiSettings.class);

// Force the IDE to repaint all windows to reflect changes immediately
ApplicationManager.getApplication().invokeLater(UIUtil::repaintAllWindows);

2. How to double the font size from "Appearance & Behavior > Appearance > Size" via API? #

Since you've already set up a custom action, implement this logic inside your action's actionPerformed method. The "Size" option in the Appearance settings maps to the global UI font size managed by UiSettings. Here's how to double it:

@Override
public void actionPerformed(AnActionEvent e) {
    Project project = e.getProject();
    if (project == null) return;

    // Fetch the global UI settings
    ApplicationSettingsManager settingsManager = ApplicationSettingsManager.getInstance();
    UiSettings uiSettings = settingsManager.getSettings(UiSettings.class);

    // Get current font size, double it (add a sanity check to avoid overly large text)
    int currentSize = uiSettings.getFontSize();
    int doubledSize = Math.min(currentSize * 2, 32); // Cap at 32 to prevent unreadable text

    // Update and save the setting
    uiSettings.setFontSize(doubledSize);
    settingsManager.saveSettings(UiSettings.class);

    // Trigger UI refresh to apply changes right away
    ApplicationManager.getApplication().invokeLater(() -> {
        UIUtil.repaintAllWindows();
        // Optional: Subscribe to settings changes to ensure full UI update
        SettingsChangedListener.EVENT_TOPIC.subscribe((source, settings) -> {
            if (settings instanceof UiSettings) {
                UIUtil.repaintAllWindows();
            }
        });
    });
}

Note for UI Scale (Percentage-Based Size) #

If your target IDE version uses percentage-based scaling (e.g., 100%, 125%) instead of fixed font sizes in the Appearance settings, use the UIDensity API instead:

UIDensity currentDensity = UIDensity.getCurrentDensity();
float newScale = Math.min(currentDensity.getScale() * 2, 2.0f); // Cap at 200% scaling
UIDensity.setCurrentDensity(new UIDensity(newScale));

// Save and refresh UI as before
ApplicationSettingsManager.getInstance().saveSettings(UiSettings.class);
ApplicationManager.getApplication().invokeLater(UIUtil::repaintAllWindows);

Keep in mind that some API details might vary slightly across IntelliJ IDEA versions, so always test against your target SDK version.

内容的提问来源于stack exchange，提问作者TTT