global desktop mode feature

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/api/GeckoEngineSettingsApiImpl.kt

@@ -23,6 +23,8 @@ import eu.weblibre.flutter_mozilla_components.pigeons.HttpsOnlyMode
 import eu.weblibre.flutter_mozilla_components.pigeons.QueryParameterStripping
 import eu.weblibre.flutter_mozilla_components.pigeons.TrackingScope
 import eu.weblibre.flutter_mozilla_components.pigeons.WebContentIsolationStrategy
+import mozilla.components.browser.state.action.ContentAction
+import mozilla.components.browser.state.action.DefaultDesktopModeAction
 import mozilla.components.concept.engine.Engine
 import mozilla.components.concept.engine.EngineSession
 import mozilla.components.concept.engine.EngineSession.TrackingProtectionPolicy
@@ -467,4 +469,36 @@ class GeckoEngineSettingsApiImpl : GeckoEngineSettingsApi {
     override fun getUseExternalDownloadManager(): Boolean {
         return GlobalComponents.useExternalDownloadManager
     }
+
+    override fun setGlobalDesktopMode(enable: Boolean, applyToExistingTabs: Boolean) {
+        val store = components.core.store
+
+        // Updates BrowserState.desktopMode, the browser-wide default applied to
+        // newly created tabs/engine sessions.
+        store.dispatch(DefaultDesktopModeAction.DesktopModeUpdated(enable))
+
+        // Only an explicit user toggle should rewrite existing tabs. Skipping this
+        // on the initial replication fire (startup / service rebuild) avoids
+        // clobbering per-tab desktop/mobile overrides and reloading loaded tabs.
+        if (!applyToExistingTabs) {
+            return
+        }
+
+        // Apply the new value to all existing regular tabs so the change takes
+        // effect immediately instead of only on tabs opened afterwards.
+        store.state.tabs.forEach { tab ->
+            if (tab.content.desktopMode == enable) return@forEach
+
+            if (tab.engineState.engineSession != null) {
+                // Loaded tab: toggle the engine session's desktop mode and reload
+                // it so the page re-renders with the new user agent / viewport.
+                components.useCases.sessionUseCases.requestDesktopSite(enable, tab.id)
+            } else {
+                // Suspended tab (no engine session yet): only update the content
+                // state so the value is applied when the tab is next loaded,
+                // without force-creating a session and waking the tab now.
+                store.dispatch(ContentAction.UpdateTabDesktopMode(tab.id, enable))
+            }
+        }
+    }
 }

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/pigeons/Gecko.g.kt

@@ -7274,6 +7274,17 @@ interface GeckoEngineSettingsApi {
    */
   fun setUseExternalDownloadManager(enabled: Boolean)
   fun getUseExternalDownloadManager(): Boolean
+  /**
+   * Sets the browser-wide default desktop mode (BrowserState.desktopMode).
+   * Newly opened tabs inherit this default; a per-tab requestDesktopSite
+   * still overrides it for that tab.
+   *
+   * When [applyToExistingTabs] is true, the new value is also applied to all
+   * currently open tabs (loaded tabs are reloaded, suspended tabs are updated
+   * in place). This should only be requested for an explicit user toggle, not
+   * during startup/replication restore, to avoid clobbering per-tab overrides.
+   */
+  fun setGlobalDesktopMode(enable: Boolean, applyToExistingTabs: Boolean)
 
   companion object {
     /** The codec used by GeckoEngineSettingsApi. */
@@ -7422,6 +7433,25 @@ interface GeckoEngineSettingsApi {
           channel.setMessageHandler(null)
         }
       }
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.flutter_mozilla_components.GeckoEngineSettingsApi.setGlobalDesktopMode$separatedMessageChannelSuffix", codec)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val enableArg = args[0] as Boolean
+            val applyToExistingTabsArg = args[1] as Boolean
+            val wrapped: List<Any?> = try {
+              api.setGlobalDesktopMode(enableArg, applyToExistingTabsArg)
+              listOf(null)
+            } catch (exception: Throwable) {
+              GeckoPigeonUtils.wrapError(exception)
+            }
+            reply.reply(wrapped)
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
     }
   }
 }

packages/flutter_mozilla_components/lib/src/domain/services/gecko_engine_settings.dart

@@ -216,4 +216,18 @@ class GeckoEngineSettingsService {
   Future<bool> getUseExternalDownloadManager() {
     return _api.getUseExternalDownloadManager();
   }
+
+  /// Sets the browser-wide default desktop mode (BrowserState.desktopMode).
+  /// Newly opened tabs inherit this default; a per-tab requestDesktopSite still
+  /// overrides it for that tab.
+  ///
+  /// Set [applyToExistingTabs] to true only for an explicit user toggle so the
+  /// new value is also applied to currently open tabs. Leave it false during
+  /// startup/replication restore to avoid clobbering per-tab overrides.
+  Future<void> setGlobalDesktopMode(
+    bool enable, {
+    bool applyToExistingTabs = false,
+  }) {
+    return _api.setGlobalDesktopMode(enable, applyToExistingTabs);
+  }
 }

packages/flutter_mozilla_components/lib/src/pigeons/gecko.g.dart

@@ -7360,6 +7360,32 @@ class GeckoEngineSettingsApi {
     ;
     return pigeonVar_replyValue! as bool;
   }
+
+  /// Sets the browser-wide default desktop mode (BrowserState.desktopMode).
+  /// Newly opened tabs inherit this default; a per-tab requestDesktopSite
+  /// still overrides it for that tab.
+  ///
+  /// When [applyToExistingTabs] is true, the new value is also applied to all
+  /// currently open tabs (loaded tabs are reloaded, suspended tabs are updated
+  /// in place). This should only be requested for an explicit user toggle, not
+  /// during startup/replication restore, to avoid clobbering per-tab overrides.
+  Future<void> setGlobalDesktopMode(bool enable, bool applyToExistingTabs) async {
+    final pigeonVar_channelName = 'dev.flutter.pigeon.flutter_mozilla_components.GeckoEngineSettingsApi.setGlobalDesktopMode$pigeonVar_messageChannelSuffix';
+    final pigeonVar_channel = BasicMessageChannel<Object?>(
+      pigeonVar_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: pigeonVar_binaryMessenger,
+    );
+    final Future<Object?> pigeonVar_sendFuture = pigeonVar_channel.send(<Object?>[enable, applyToExistingTabs]);
+    final pigeonVar_replyList = await pigeonVar_sendFuture as List<Object?>?;
+
+    _extractReplyValueOrThrow(
+        pigeonVar_replyList,
+        pigeonVar_channelName,
+        isNullValid: true,
+    )
+    ;
+  }
 }
 
 class GeckoSessionApi {

packages/flutter_mozilla_components/pigeons/gecko.dart

@@ -1561,6 +1561,16 @@ abstract class GeckoEngineSettingsApi {
   void setUseExternalDownloadManager(bool enabled);
 
   bool getUseExternalDownloadManager();
+
+  /// Sets the browser-wide default desktop mode (BrowserState.desktopMode).
+  /// Newly opened tabs inherit this default; a per-tab requestDesktopSite
+  /// still overrides it for that tab.
+  ///
+  /// When [applyToExistingTabs] is true, the new value is also applied to all
+  /// currently open tabs (loaded tabs are reloaded, suspended tabs are updated
+  /// in place). This should only be requested for an explicit user toggle, not
+  /// during startup/replication restore, to avoid clobbering per-tab overrides.
+  void setGlobalDesktopMode(bool enable, bool applyToExistingTabs);
 }
 
 @HostApi()