debug: reduce callstack flashing by showing a stale remainder of the callstack

#25605

2 files changed, 14 insertions, 0 deletions

diff --git a/src/vs/workbench/parts/debug/common/debugModel.ts b/src/vs/workbench/parts/debug/common/debugModel.ts
index 2ec0be9c6af..1f3e082dc63 100644
--- a/src/vs/workbench/parts/debug/common/debugModel.ts
+++ b/src/vs/workbench/parts/debug/common/debugModel.ts
@@ -373,6 +373,7 @@ export class StackFrame implements IStackFrame {
 export class Thread implements IThread {
 	private fetchPromise: TPromise<void>;
 	private callStack: IStackFrame[];
+	private staleCallStack: IStackFrame[];
 	public stoppedDetails: IRawStoppedDetails;
 	public stopped: boolean;
 
@@ -380,6 +381,7 @@ export class Thread implements IThread {
 		this.fetchPromise = null;
 		this.stoppedDetails = null;
 		this.callStack = [];
+		this.staleCallStack = [];
 		this.stopped = false;
 	}
 
@@ -389,6 +391,9 @@ export class Thread implements IThread {
 
 	public clearCallStack(): void {
 		this.fetchPromise = null;
+		if (this.callStack.length) {
+			this.staleCallStack = this.callStack;
+		}
 		this.callStack = [];
 	}
 
@@ -396,6 +401,10 @@ export class Thread implements IThread {
 		return this.callStack;
 	}
 
+	public getStaleCallStack(): IStackFrame[] {
+		return this.staleCallStack;
+	}
+
 	/**
 	 * Queries the debug adapter for the callstack and returns a promise
 	 * which completes once the call stack has been retrieved.
diff --git a/src/vs/workbench/parts/debug/electron-browser/debugViewer.ts b/src/vs/workbench/parts/debug/electron-browser/debugViewer.ts
index 5450d5d5099..2c8391b709f 100644
--- a/src/vs/workbench/parts/debug/electron-browser/debugViewer.ts
+++ b/src/vs/workbench/parts/debug/electron-browser/debugViewer.ts
@@ -366,6 +366,11 @@ export class CallStackDataSource implements IDataSource {
 		if (!callStack) {
 			return [];
 		}
+		if (callStack.length === 1) {
+			// To reduce flashing of the call stack view simply append the stale call stack
+			// once we have the correct data the tree will refresh and we will no longer display it.
+			return callStack.concat(thread.getStaleCallStack().slice(1));
+		}
 
 		if (thread.stoppedDetails && thread.stoppedDetails.framesErrorMessage) {
 			return callStack.concat([thread.stoppedDetails.framesErrorMessage]);