debug: add run statusbar item

- adds the `select and run` statusbar item for debugging.
- the item is registered when a debug session starts, and reflects the
  current configuration.
- triggering the item will prompt the debug prefix quick-open menu.

Signed-off-by: vince-fugnitto <vincent.fugnitto@ericsson.com>

packages/debug/src/browser/debug-preferences.ts

@@ -44,6 +44,11 @@ export const debugPreferencesSchema: PreferenceSchema = {
             type: 'boolean',
             default: false,
             description: 'Show variable values inline in editor while debugging.'
+        },
+        'debug.showInStatusBar': {
+            enum: ['never', 'always', 'onFirstSessionStart'],
+            description: 'Controls when the debug status bar should be visible.',
+            default: 'onFirstSessionStart'
         }
     }
 };
@@ -54,6 +59,7 @@ export class DebugConfiguration {
     'debug.openDebug': 'neverOpen' | 'openOnSessionStart' | 'openOnFirstSessionStart' | 'openOnDebugBreak';
     'debug.internalConsoleOptions': 'neverOpen' | 'openOnSessionStart' | 'openOnFirstSessionStart';
     'debug.inlineValues': boolean;
+    'debug.showInStatusBar': 'never' | 'always' | 'onFirstSessionStart';
 }
 
 export const DebugPreferences = Symbol('DebugPreferences');

packages/debug/src/browser/debug-prefix-configuration.ts

@@ -14,7 +14,7 @@
  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  ********************************************************************************/
 
-import { inject, injectable } from 'inversify';
+import { inject, injectable, postConstruct } from 'inversify';
 import { Command, CommandContribution, CommandHandler, CommandRegistry } from '@theia/core/lib/common/command';
 import {
     QuickOpenContribution, QuickOpenHandler, QuickOpenModel,
@@ -27,6 +27,8 @@ import { DebugSessionOptions } from './debug-session-options';
 import { WorkspaceService } from '@theia/workspace/lib/browser';
 import { LabelProvider } from '@theia/core/lib/browser/label-provider';
 import URI from '@theia/core/lib/common/uri';
+import { StatusBar, StatusBarAlignment } from '@theia/core/lib/browser';
+import { DebugPreferences } from './debug-preferences';
 
 @injectable()
 export class DebugPrefixConfiguration implements CommandContribution, CommandHandler, QuickOpenContribution, QuickOpenHandler, QuickOpenModel {
@@ -37,6 +39,9 @@ export class DebugPrefixConfiguration implements CommandContribution, CommandHan
     @inject(DebugSessionManager)
     protected readonly debugSessionManager: DebugSessionManager;
 
+    @inject(DebugPreferences)
+    protected readonly preference: DebugPreferences;
+
     @inject(DebugConfigurationManager)
     protected readonly debugConfigurationManager: DebugConfigurationManager;
 
@@ -49,15 +54,34 @@ export class DebugPrefixConfiguration implements CommandContribution, CommandHan
     @inject(LabelProvider)
     protected readonly labelProvider: LabelProvider;
 
+    @inject(StatusBar)
+    protected readonly statusBar: StatusBar;
+
     readonly prefix = 'debug ';
     readonly description = 'Debug Configuration';
+    readonly statusBarId = 'select-run-debug-statusbar-item';
 
     private readonly command: Command = {
         id: 'select.debug.configuration',
         category: 'Debug',
         label: 'Select and Start Debugging'
     };
 
+    @postConstruct()
+    protected update(): void {
+        this.handleDebugStatusBarVisibility();
+        this.preference.onPreferenceChanged(e => {
+            if (e.preferenceName === 'debug.showInStatusBar') {
+                this.handleDebugStatusBarVisibility();
+            }
+        });
+        const toDisposeOnStart = this.debugSessionManager.onDidStartDebugSession(() => {
+            toDisposeOnStart.dispose();
+            this.handleDebugStatusBarVisibility(true);
+            this.debugConfigurationManager.onDidChange(() => this.handleDebugStatusBarVisibility(true));
+        });
+    }
+
     execute(): void {
         this.prefixQuickOpenService.open(this.prefix);
     }
@@ -119,4 +143,39 @@ export class DebugPrefixConfiguration implements CommandContribution, CommandHan
         this.debugConfigurationManager.current = { ...configuration };
         this.commandRegistry.executeCommand(DebugCommands.START.id);
     }
+
+    /**
+     * Handle the visibility of the debug status bar.
+     * @param event the preference change event.
+     */
+    protected handleDebugStatusBarVisibility(started?: boolean): void {
+        const showInStatusBar = this.preference['debug.showInStatusBar'];
+        if (showInStatusBar === 'never') {
+            return this.removeDebugStatusBar();
+        } else if (showInStatusBar === 'always' || started) {
+            return this.updateStatusBar();
+        }
+    }
+
+    /**
+     * Update the debug status bar element based on the current configuration.
+     */
+    protected updateStatusBar(): void {
+        const text: string = this.debugConfigurationManager.current
+            ? this.debugConfigurationManager.current.configuration.name
+            : '';
+        this.statusBar.setElement(this.statusBarId, {
+            alignment: StatusBarAlignment.LEFT,
+            text: '$(play) ' + text,
+            tooltip: this.command.label,
+            command: this.command.id,
+        });
+    }
+
+    /**
+     * Remove the debug status bar element.
+     */
+    protected removeDebugStatusBar(): void {
+        this.statusBar.removeElement(this.statusBarId);
+    }
 }