WIP

This fixes the issue of DevTools windows not appearing (#8029). Currently, this only would resolve the issue for Deep Links.

Author: jwren

flutter-idea/src/io/flutter/deeplinks/DeepLinksViewFactory.java

@@ -18,6 +18,7 @@
 import io.flutter.sdk.FlutterSdkVersion;
 import io.flutter.utils.AsyncUtils;
 import io.flutter.utils.OpenApiUtils;
+import io.flutter.view.ViewUtils;
 import kotlin.coroutines.Continuation;
 import org.jetbrains.annotations.NotNull;
 
@@ -27,18 +28,63 @@
 public class DeepLinksViewFactory implements ToolWindowFactory {
   @NotNull private static String TOOL_WINDOW_ID = "Flutter Deep Links";
 
+  @NotNull
+  private final ViewUtils viewUtils = new ViewUtils();
+
   @Override
   public Object isApplicableAsync(@NotNull Project project, @NotNull Continuation<? super Boolean> $completion) {
-    FlutterSdk sdk = FlutterSdk.getFlutterSdk(project);
-    FlutterSdkVersion sdkVersion = sdk == null ? null : sdk.getVersion();
-    return sdkVersion != null && sdkVersion.canUseDeepLinksTool();
+    // Due to https://github.com/flutter/flutter/issues/142521, this always returns true when the
+    // Flutter IJ plugin is installed.
+
+    // The logic which asserts that the Flutter SDK is up to date enough for this particular feature
+    // is captured in the implementation of createToolWindowContent() below.
+
+    return true;
   }
 
   @Override
   public void createToolWindowContent(@NotNull Project project, @NotNull ToolWindow toolWindow) {
-    FlutterSdk sdk = FlutterSdk.getFlutterSdk(project);
-    FlutterSdkVersion sdkVersion = sdk == null ? null : sdk.getVersion();
+    final FlutterSdk flutterSdk = FlutterSdk.getFlutterSdk(project);
+    final FlutterSdkVersion flutterSdkVersion = flutterSdk == null ? null : flutterSdk.getVersion();
+
+    // There are four potential states for the Flutter SDK:
+    // 1. The Flutter SDK is null (flutterSdk == null) (an SDK path is invalid or not configured)
+    // 2. The Flutter SDK exists, but version file information is unavailable (flutterSdkVersion == null),
+    //      see https://github.com/flutter/flutter/issues/142521.
+    // 3. The Flutter SDK exists, and the version file information is available, but this tool is not
+    //      available on the version of the SDK that the user has.
+    // 4. The Flutter SDK exists with valid version information.
+
+    // First case:
+    if (flutterSdk == null) {
+      viewUtils.presentLabels(toolWindow, List.of("Set the Flutter SDK path in",
+                                                  "Settings > Languages & Frameworks > Flutter,",
+                                                  "and then restart the IDE."));
+      return;
+    }
+
+    // Second case:
+    if (flutterSdk.getVersion().fullVersion().equals(FlutterSdkVersion.UNKNOWN_VERSION)) {
+      viewUtils.presentLabels(toolWindow, List.of("A Flutter SDK was found at the location",
+                                                  "specified in the settings, however the directory",
+                                                  "is in an incomplete state. To fix, shut down the IDE,",
+                                                  "run `flutter doctor` or `flutter --version` in the",
+                                                  "Flutter SDK directory, and then restart the IDE."));
+      return;
+    }
+
+    // Third case:
+    if (!flutterSdkVersion.canUseDeepLinksTool()) {
+      final String versionText = flutterSdkVersion.fullVersion();
+      viewUtils.presentLabels(toolWindow, List.of("The version of your Flutter SDK,",
+                                                  versionText + ",",
+                                                  "is not recent enough to use this tool.",
+                                                  "Update the Flutter SDK, `flutter upgrade`,",
+                                                  "and then restart the IDE."));
+      return;
+    }
 
+    // Final case:
     AsyncUtils.whenCompleteUiThread(
       DevToolsService.getInstance(project).getDevToolsInstance(),
       (instance, error) -> {
@@ -60,7 +106,7 @@ public void createToolWindowContent(@NotNull Project project, @NotNull ToolWindo
           .setDevToolsPort(instance.port())
           .setPage("deep-links")
           .setEmbed(true)
-          .setFlutterSdkVersion(sdkVersion)
+          .setFlutterSdkVersion(flutterSdkVersion)
           .setWorkspaceCache(WorkspaceCache.getInstance(project))
           .setIdeFeature(DevToolsIdeFeature.TOOL_WINDOW)
           .build();

flutter-idea/src/io/flutter/sdk/FlutterSdkVersion.java

@@ -49,6 +49,9 @@ 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 String UNKNOWN_VERSION = "unknown version";
+
   @Nullable
   private final Version version;
   @Nullable
@@ -153,7 +156,7 @@ public boolean isValid() {
 
   @NotNull
   public String fullVersion() {
-    return version == null ? "unknown version" : Objects.requireNonNull(version.toString());
+    return version == null ? UNKNOWN_VERSION : Objects.requireNonNull(version.toString());
   }
 
   /**
@@ -167,7 +170,7 @@ public String getVersionText() {
   @Override
   @NotNull
   public String toString() {
-    return version == null ? "unknown version" : Objects.requireNonNull(version.toCompactString());
+    return version == null ? UNKNOWN_VERSION : Objects.requireNonNull(version.toCompactString());
   }
 
   @Override

flutter-idea/src/io/flutter/view/ViewUtils.java

@@ -15,6 +15,7 @@
 import com.intellij.util.ui.UIUtil;
 import io.flutter.utils.LabelInput;
 import io.flutter.utils.OpenApiUtils;
+import org.jetbrains.annotations.NotNull;
 
 import javax.swing.*;
 import java.awt.*;
@@ -27,6 +28,33 @@ public void presentLabel(ToolWindow toolWindow, String text) {
     replacePanelLabel(toolWindow, label);
   }
 
+  /**
+   * Displays multiple labels vertically centered in the tool window.
+   *
+   * @param toolWindow The target tool window.
+   * @param labels     A list of strings to display as labels.
+   */
+  public void presentLabels(@NotNull ToolWindow toolWindow, @NotNull List<String> labels) {
+    final JPanel labelsPanel = new JPanel(new GridLayout(0, 1));
+    labelsPanel.setBorder(JBUI.Borders.empty()); // Use padding on individual labels if needed
+
+    for (String text : labels) {
+      final JBLabel label = new JBLabel(text, SwingConstants.CENTER);
+      label.setForeground(UIUtil.getLabelDisabledForeground());
+      // Add padding to each label for spacing
+      label.setBorder(JBUI.Borders.empty(2, 0));
+      labelsPanel.add(label);
+    }
+
+    // Use VerticalFlowLayout to center the block of labels vertically
+    final JPanel centerPanel = new JPanel(new VerticalFlowLayout(VerticalFlowLayout.CENTER));
+    centerPanel.add(labelsPanel);
+
+    replacePanelLabel(toolWindow, centerPanel);
+  }
+
+
+
   public void presentClickableLabel(ToolWindow toolWindow, List<LabelInput> labels) {
     final JPanel panel = new JPanel(new GridLayout(0, 1));