Add widget previewer tool window

resources/META-INF/plugin.xml

@@ -329,9 +329,11 @@
     <toolWindow id="Flutter Deep Links" anchor="right" icon="FlutterIcons.DevToolsDeepLinks" factoryClass="io.flutter.deeplinks.DeepLinksViewFactory" />
     <toolWindow id="Flutter DevTools" anchor="right" icon="FlutterIcons.DevTools" factoryClass="io.flutter.devtools.RemainingDevToolsViewFactory" />
     <toolWindow id="Flutter DevTools Extensions" anchor="right" icon="FlutterIcons.DevToolsExtensions" factoryClass="io.flutter.devtools.DevToolsExtensionsViewFactory" />
-    <!-- Do not uncomment until ready to release the Property Editor. -->
     <toolWindow id="Flutter Property Editor" anchor="right" icon="FlutterIcons.PropertyEditor" factoryClass="io.flutter.propertyeditor.PropertyEditorViewFactory" />
-
+    <toolWindow id="Flutter Widget Preview"
+                anchor="right"
+                factoryClass="io.flutter.widgetpreview.WidgetPreviewToolWindowFactory"
+                icon="FlutterIcons.WidgetPreview" />
     <!-- Having the projectService defined after the toolWindows allows them to all be picked up by the platform -->
     <!-- See https://github.com/flutter/flutter-intellij/issues/8029 -->
     <projectService serviceImplementation="io.flutter.view.InspectorView" overrides="false"/>

src/icons/FlutterIcons.java

@@ -9,6 +9,7 @@ private static Icon load(String path) {
     return IconLoader.getIcon(path, FlutterIcons.class);
   }
 
+  public static final Icon WidgetPreview = load("/icons/expui/widgetPreview.svg");
   public static final Icon DevToolsDeepLinks = load("/icons/expui/deepLinks.svg");
   public static final Icon DevTools = load("/icons/expui/devTools.svg");
   public static final Icon DevToolsExtensions = load("/icons/expui/extensions.svg");

src/io/flutter/FlutterBundle.properties

@@ -187,3 +187,10 @@ icon.preview.disallow.flutter_vector_icons=Package "flutter_vector_icons" cannot
 icon.preview.disallow.material_design_icons_flutter=Package "material_design_icons_flutter" always displays blank icon previews.
 icon.preview.disallow.package.title=Unsupported icon package
 icon.preview.analysis=Checking icons...
+
+widget.preview.initializing=Initializing Flutter Widget Preview...
+widget.preview.starting=Starting Flutter Widget Preview web server...
+widget.preview.loading=Loading Flutter Widget Preview at {0}...
+widget.preview.error=Error: {0}
+widget.preview.sdk.too.old=Flutter SDK version is too old for Flutter Widget Preview. Please update your SDK.
+flutter.sdk.not.found=Flutter SDK not found.

src/io/flutter/devtools/AbstractDevToolsViewFactory.java

@@ -19,6 +19,7 @@
 import io.flutter.sdk.FlutterSdkVersion;
 import io.flutter.utils.AsyncUtils;
 import io.flutter.utils.OpenApiUtils;
+import io.flutter.view.DevToolsUrlProvider;
 import io.flutter.view.EmbeddedBrowser;
 import io.flutter.view.ViewUtils;
 import kotlin.coroutines.Continuation;
@@ -156,7 +157,7 @@ private void loadDevToolsInEmbeddedBrowser(@NotNull Project project,
               FlutterUtils.embeddedBrowser(project))
             .ifPresent(embeddedBrowser ->
                        {
-                         embeddedBrowser.openPanel(toolWindow, getToolWindowTitle(), getToolWindowIcon(), devToolsUrl, System.out::println,
+                         embeddedBrowser.openPanel(toolWindow, getToolWindowTitle(), getToolWindowIcon(), new DevToolsUrlProvider(devToolsUrl), System.out::println,
                                                    warningMessage);
                          devToolsLoadedInBrowser = true;
                          doAfterBrowserOpened(project, embeddedBrowser);

src/io/flutter/devtools/DevToolsUrl.java

@@ -214,13 +214,14 @@ public String getUrlString() {
     return "http://" + devToolsHost + ":" + devToolsPort + "/" + (page != null ? page : "") + "?" + String.join("&", params);
   }
 
-  public void maybeUpdateColor() {
+  public boolean maybeUpdateColor() {
     final String newColor = devToolsUtils.getColorHexCode();
     if (Objects.equals(colorHexCode, newColor)) {
-      return;
+      return false;
     }
 
     colorHexCode = newColor;
     isBright = devToolsUtils.getIsBackgroundBright();
+    return true;
   }
 }

src/io/flutter/jxbrowser/EmbeddedJxBrowser.java

@@ -232,7 +232,7 @@ private EmbeddedJxBrowser(@NotNull Project project) {
     };
   }
 
-  private void manageJxBrowserDownload(ContentManager contentManager) {
+  private void manageJxBrowserDownload(@NotNull ContentManager contentManager) {
     final JxBrowserStatus jxBrowserStatus = jxBrowserManager.getStatus();
 
     if (jxBrowserStatus.equals(JxBrowserStatus.INSTALLED)) {
@@ -289,7 +289,7 @@ else if (jxBrowserStatus.equals(JxBrowserStatus.INSTALLATION_FAILED)) {
     }
   }
 
-  protected void handleJxBrowserInstallationFailed(ContentManager contentManager) {
+  protected void handleJxBrowserInstallationFailed(@NotNull ContentManager contentManager) {
     final List<LabelInput> inputs = new ArrayList<>();
 
     final InstallationFailedReason latestFailureReason = jxBrowserManager.getLatestFailureReason();

src/io/flutter/logging/FlutterConsoleLogManager.java

@@ -394,7 +394,7 @@ public void actionPerformed(@NotNull AnActionEvent event) {
         Project project = app.getProject();
         if (!project.isDisposed()) {
           final EmbeddedBrowser browser = FlutterUtils.embeddedBrowser(project);
-          if (browser != null) {
+          if (browser != null && widgetId != null) {
             browser.updatePanelToWidget(widgetId);
           }
         }

src/io/flutter/sdk/FlutterCommand.java

@@ -100,6 +100,27 @@ protected boolean isPubRelatedCommand() {
     return pubRelatedCommands.contains(type);
   }
 
+  /**
+   * Starts running the command and returns the raw `Process` object.
+   *
+   * <p>This is intended for commands that need direct stream access and do not need console integration.
+   *
+   * @return the started `Process`, or null if an exception occurred.
+   */
+  @Nullable
+  public Process start() {
+    final GeneralCommandLine commandLine = createGeneralCommandLine(null);
+    final String commandText = safeCommandLog(commandLine);
+    LOG.info(commandText);
+    try {
+      return commandLine.createProcess();
+    }
+    catch (ExecutionException e) {
+      LOG.error("Failed to start Flutter command: " + commandText, e);
+      return null;
+    }
+  }
+
   /**
    * Starts running the command, without showing its output in a console.
    * <p>
@@ -307,6 +328,7 @@ enum Type {
     RUN("Flutter run", "run"),
     UPGRADE("Flutter upgrade", "upgrade"),
     VERSION("Flutter version", "--version"),
+    WIDGET_PREVIEW("Flutter widget preview", "widget-preview"),
     TEST("Flutter test", "test");
 
     final public String title;

src/io/flutter/sdk/FlutterSdk.java

@@ -415,6 +415,19 @@ public FlutterCommand flutterTest(@NotNull PubRoot root, @NotNull VirtualFile fi
     return new FlutterCommand(this, root.getRoot(), FlutterCommand.Type.TEST, args.toArray(new String[]{ }));
   }
 
+  @NotNull
+  public FlutterCommand widgetPreview(@NotNull PubRoot root, boolean isVerboseMode) {
+    final List<String> args = new ArrayList<>();
+    args.add("start");
+    args.add("--web-server");
+    args.add("--machine");
+    if (isVerboseMode) {
+      args.add("--verbose");
+    }
+
+    return new FlutterCommand(this, root.getRoot(), FlutterCommand.Type.WIDGET_PREVIEW, args.toArray(new String[]{}));
+  }
+
   /**
    * Runs flutter create and waits for it to finish.
    * <p>

src/io/flutter/sdk/FlutterSdkVersion.java

@@ -60,6 +60,9 @@ public final class FlutterSdkVersion implements Comparable<FlutterSdkVersion> {
   @NotNull
   public static final FlutterSdkVersion MIN_SUPPORTS_PROPERTY_EDITOR = new FlutterSdkVersion("3.32.0-0.1.pre");
 
+  @NotNull
+  public static final FlutterSdkVersion MIN_SUPPORTS_WIDGET_PREVIEW = new FlutterSdkVersion("3.38.0-0.0.pre");
+
   @NotNull
   public static final String UNKNOWN_VERSION = "unknown version";
 
@@ -170,6 +173,10 @@ public boolean canUsePropertyEditor() {
     return supportsVersion(MIN_SUPPORTS_PROPERTY_EDITOR);
   }
 
+  public boolean canUseWidgetPreview() {
+    return supportsVersion(MIN_SUPPORTS_WIDGET_PREVIEW);
+  }
+
   public boolean canUseDevToolsMultiEmbed() {
     return supportsVersion(MIN_SUPPORTS_DEVTOOLS_MULTI_EMBED);
   }

src/io/flutter/view/BrowserUrlProvider.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2025 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+package io.flutter.view;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Saves a browser URL that may be editable depending on additional settings from the IDE or running applications.
+ */
+public interface BrowserUrlProvider {
+  void setWidgetId(@NotNull String widgetId);
+
+  @NotNull String getBrowserUrl();
+
+  boolean maybeUpdateColor();
+
+  boolean setVmServiceUri(@NotNull String vmServiceUri);
+}

src/io/flutter/view/DevToolsUrlProvider.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2025 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+package io.flutter.view;
+
+import io.flutter.devtools.DevToolsUrl;
+import org.jetbrains.annotations.NotNull;
+
+public record DevToolsUrlProvider(@NotNull DevToolsUrl url) implements BrowserUrlProvider {
+  @Override
+  public void setWidgetId(@NotNull String widgetId) {
+    url.widgetId = widgetId;
+  }
+
+  @Override
+  public @NotNull String getBrowserUrl() {
+    return url.getUrlString();
+  }
+
+  @Override
+  public boolean maybeUpdateColor() {
+    return url.maybeUpdateColor();
+  }
+
+  @Override
+  public boolean setVmServiceUri(@NotNull String newVmServiceUri) {
+    if (url.vmServiceUri != null && url.vmServiceUri.equals(newVmServiceUri)) {
+      return false;
+    }
+    url.vmServiceUri = newVmServiceUri;
+    return true;
+  }
+}