[Themes] Automatic theme for light/dark

- Eclipse's ThemeEngine will try to automatically set the light or dark theme on startup if the themeid setting is not present in the org.eclipse.e4.ui.css.swt.theme.prefs file or that file doesn't exist (fresh workspace) - We'll expose this in Preferences as a new automatic pseudo theme. This will delete the themeid setting so that the auto theming occurs on startup
archimatetool · Sep 15, 2024 · e69890a · e69890a
1 parent 4864d8f
commit e69890a
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Showing 5 changed files with 58 additions and 6 deletions.
diff --git a/...chimatetool.editor/src/com/archimatetool/editor/preferences/AppearancePreferencePage.java b/...chimatetool.editor/src/com/archimatetool/editor/preferences/AppearancePreferencePage.java
@@ -5,6 +5,9 @@
  */
 package com.archimatetool.editor.preferences;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.e4.ui.css.swt.theme.ITheme;
 import org.eclipse.e4.ui.css.swt.theme.IThemeEngine;
@@ -24,6 +27,7 @@
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.IWorkbenchPreferencePage;
@@ -58,6 +62,22 @@ public class AppearancePreferencePage
     private IThemeEngine themeEngine;
     private ITheme lastActiveTheme;
 
+    /**
+     * Pseudo theme to set automatic light/dark on startup
+     */
+    private static ITheme AUTOMATIC_THEME = new ITheme() {
+        @Override
+        public String getId() {
+            return Display.isSystemDarkTheme() ? ThemeUtils.E4_DARK_THEME_ID : ThemeUtils.E4_DEFAULT_THEME_ID;
+        }
+
+        @Override
+        public String getLabel() {
+            return Messages.AppearancePreferencePage_7;
+        }
+    };
+
+
 	public AppearancePreferencePage() {
 		setPreferenceStore(ArchiPlugin.PREFERENCES);
 		setDescription(Messages.AppearancePreferencePage_0);
@@ -135,7 +155,7 @@ public String getText(Object element) {
                 @Override
                 public void selectionChanged(SelectionChangedEvent event) {
                     ITheme theme = (ITheme)((IStructuredSelection)fThemeComboViewer.getSelection()).getFirstElement();
-                    themeEngine.setTheme(theme, false);
+                    themeEngine.setTheme(theme.getId(), false); // set theme id, not theme in case of automatic theme
                 }
             });
         }
@@ -146,11 +166,20 @@ public void selectionChanged(SelectionChangedEvent event) {
     private void setValues() {
         // Themes list
         if(themeEngine != null) {
-            fThemeComboViewer.setInput(themeEngine.getThemes().toArray());
+            List<ITheme> themes = new ArrayList<>((themeEngine.getThemes()));
+            themes.add(0, AUTOMATIC_THEME);
 
-            ITheme activeTheme = themeEngine.getActiveTheme();
-            if(activeTheme != null) {
-                fThemeComboViewer.setSelection(new StructuredSelection(activeTheme));
+            fThemeComboViewer.setInput(themes.toArray());
+
+            // If themeid is not present the ThemeEngine will try to set light/dark theme based on OS theme
+            if(ThemeUtils.getThemePreferences().get(ThemeUtils.THEMEID_KEY, null) == null) {
+                fThemeComboViewer.setSelection(new StructuredSelection(AUTOMATIC_THEME));
+            }
+            else {
+                ITheme activeTheme = themeEngine.getActiveTheme();
+                if(activeTheme != null) {
+                    fThemeComboViewer.setSelection(new StructuredSelection(activeTheme));
+                }
             }
         }
 
@@ -170,7 +199,19 @@ public boolean performOk() {
         // Theme
         if(themeEngine != null) {
             ITheme theme = (ITheme)((IStructuredSelection)fThemeComboViewer.getSelection()).getFirstElement();
-            if(!theme.equals(lastActiveTheme)) {
+
+            if(theme == AUTOMATIC_THEME) {
+                // Just remove the "themeid" key and then the ThemeEngine will use dark/light depending on OS theme on startup
+                IEclipsePreferences themePrefs = ThemeUtils.getThemePreferences();
+                themePrefs.remove(ThemeUtils.THEMEID_KEY);
+                try {
+                    themePrefs.flush();
+                }
+                catch(BackingStoreException ex) {
+                    ex.printStackTrace();
+                }
+            }
+            else {
                 themeEngine.setTheme(theme, true);
                 lastActiveTheme = theme;
             }
@@ -192,6 +233,7 @@ public boolean performOk() {
             swtPrefs.flush();
         }
         catch(BackingStoreException ex) {
+            ex.printStackTrace();
         }
 
         // Mac native item heights

diff --git a/com.archimatetool.editor/src/com/archimatetool/editor/preferences/Messages.java b/com.archimatetool.editor/src/com/archimatetool/editor/preferences/Messages.java
@@ -25,6 +25,8 @@ public class Messages extends NLS {
 
     public static String AppearancePreferencePage_6;
 
+    public static String AppearancePreferencePage_7;
+
     public static String ColoursPreferencePage_0;
 
     public static String ColoursPreferencePage_1;

diff --git a/com.archimatetool.editor/src/com/archimatetool/editor/preferences/messages.properties b/com.archimatetool.editor/src/com/archimatetool/editor/preferences/messages.properties
@@ -5,6 +5,7 @@ AppearancePreferencePage_3=Use round tabs
 AppearancePreferencePage_4=Enable Theming
 AppearancePreferencePage_5=Use larger (Mac native) row heights
 AppearancePreferencePage_6=Requires a restart
+AppearancePreferencePage_7=Automatically select Light/Dark
 
 ColoursPreferencePage_0=Default colours for objects:
 ColoursPreferencePage_1=Strategy elements

diff --git a/com.archimatetool.editor/src/com/archimatetool/editor/ui/ThemeUtils.java b/com.archimatetool.editor/src/com/archimatetool/editor/ui/ThemeUtils.java
@@ -56,6 +56,11 @@ public final class ThemeUtils {
      */
     public static final String THEME_ENABLED = "themeEnabled";
 
+    /**
+     * Used in .metadata/.plugins/org.eclipse.core.runtime/.settings/org.eclipse.e4.ui.css.swt.theme.prefs to store current theme id
+     */
+    public static final String THEMEID_KEY = "themeid";
+
     private static IThemeEngine engine;
 
     /**

diff --git a/com.archimatetool.help/help/Text/prefs_appearance.html b/com.archimatetool.help/help/Text/prefs_appearance.html
@@ -20,6 +20,8 @@ <h2>Appearance</h2>
 
     <p><strong>Theme</strong><br/>
 	Choose the theme to use for Archi. A restart will be required for this change to fully take effect.</p>
+
+    <p>If the theme is set to "Automatically select Light/Dark" the theme will be set according to the current operating system theme of light or dark when starting Archi. Some system dark themes are not supported and so this setting might not work. If this is the case, select another theme to suit the host system theme.</p>
 
 	<p><strong>Use round tabs</strong><br/>
     Whether to use round or square tabs.</p>