feat(vscode-ide-companion): add cancel streaming functionality

- Add handleCancel callback to App component
- Implement cancelStreaming message posting to VS Code
- Add onCancel prop to InputForm component
- Replace send button with stop button during streaming

packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.ts

@@ -5,6 +5,9 @@
  */
 
 import * as vscode from 'vscode';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
 import { BaseMessageHandler } from './BaseMessageHandler.js';
 import { getFileName } from '../utils/webviewUtils.js';
 
@@ -20,6 +23,7 @@ export class FileMessageHandler extends BaseMessageHandler {
       'getWorkspaceFiles',
       'openFile',
       'openDiff',
+      'createAndOpenTempFile',
     ].includes(messageType);
   }
 
@@ -47,6 +51,10 @@ export class FileMessageHandler extends BaseMessageHandler {
         await this.handleOpenDiff(data);
         break;
 
+      case 'createAndOpenTempFile':
+        await this.handleCreateAndOpenTempFile(data);
+        break;
+
       default:
         console.warn(
           '[FileMessageHandler] Unknown message type:',
@@ -347,4 +355,52 @@ export class FileMessageHandler extends BaseMessageHandler {
       vscode.window.showErrorMessage(`Failed to open diff: ${error}`);
     }
   }
+
+  /**
+   * Create and open temporary file
+   */
+  private async handleCreateAndOpenTempFile(
+    data: Record<string, unknown> | undefined,
+  ): Promise<void> {
+    if (!data) {
+      console.warn(
+        '[FileMessageHandler] No data provided for createAndOpenTempFile',
+      );
+      return;
+    }
+
+    try {
+      const content = (data.content as string) || '';
+      const fileName = (data.fileName as string) || 'temp';
+      const fileExtension = (data.fileExtension as string) || '.txt';
+
+      // Create temporary file path
+      const tempDir = os.tmpdir();
+      const tempFileName = `${fileName}-${Date.now()}${fileExtension}`;
+      const tempFilePath = path.join(tempDir, tempFileName);
+
+      // Write content to temporary file
+      await fs.promises.writeFile(tempFilePath, content, 'utf8');
+
+      // Open the temporary file in VS Code
+      const uri = vscode.Uri.file(tempFilePath);
+      await vscode.window.showTextDocument(uri, {
+        preview: false,
+        preserveFocus: false,
+      });
+
+      console.log(
+        '[FileMessageHandler] Created and opened temporary file:',
+        tempFilePath,
+      );
+    } catch (error) {
+      console.error(
+        '[FileMessageHandler] Failed to create and open temporary file:',
+        error,
+      );
+      vscode.window.showErrorMessage(
+        `Failed to create and open temporary file: ${error}`,
+      );
+    }
+  }
 }

packages/vscode-ide-companion/src/webview/handlers/SessionMessageHandler.ts

@@ -25,6 +25,7 @@ export class SessionMessageHandler extends BaseMessageHandler {
       'getQwenSessions',
       'saveSession',
       'resumeSession',
+      'cancelStreaming',
       // UI action: open a new chat tab (new WebviewPanel)
       'openNewChatTab',
     ].includes(messageType);
@@ -102,6 +103,11 @@ export class SessionMessageHandler extends BaseMessageHandler {
         }
         break;
 
+      case 'cancelStreaming':
+        // Handle cancel streaming request from webview
+        await this.handleCancelStreaming();
+        break;
+
       default:
         console.warn(
           '[SessionMessageHandler] Unknown message type:',
@@ -910,6 +916,34 @@ export class SessionMessageHandler extends BaseMessageHandler {
     }
   }
 
+  /**
+   * Handle cancel streaming request
+   */
+  private async handleCancelStreaming(): Promise<void> {
+    try {
+      console.log('[SessionMessageHandler] Canceling streaming...');
+
+      // Cancel the current streaming operation in the agent manager
+      await this.agentManager.cancelCurrentPrompt();
+
+      // Send streamEnd message to WebView to update UI
+      this.sendToWebView({
+        type: 'streamEnd',
+        data: { timestamp: Date.now(), reason: 'user_cancelled' },
+      });
+
+      console.log('[SessionMessageHandler] Streaming cancelled successfully');
+    } catch (_error) {
+      console.log('[SessionMessageHandler] Streaming cancelled (interrupted)');
+
+      // Always send streamEnd to update UI, regardless of errors
+      this.sendToWebView({
+        type: 'streamEnd',
+        data: { timestamp: Date.now(), reason: 'user_cancelled' },
+      });
+    }
+  }
+
   /**
    * Handle resume session request
    */