prevent editor taking up more than its share

fixes #79897

src/vs/workbench/browser/layout.ts

@@ -608,6 +608,23 @@ export abstract class Layout extends Disposable implements IWorkbenchLayoutServi
 		return offset;
 	}
 
+	getMaximumEditorDimensions(): Dimension {
+		const takenWidth =
+			(this.isVisible(Parts.ACTIVITYBAR_PART) ? this.activityBarPartView.minimumWidth : 0) +
+			(this.isVisible(Parts.SIDEBAR_PART) ? this.sideBarPartView.minimumWidth : 0) +
+			(this.isVisible(Parts.PANEL_PART) && this.state.panel.position === Position.RIGHT ? this.panelPartView.minimumWidth : 0);
+
+		const takenHeight =
+			(this.isVisible(Parts.TITLEBAR_PART) ? this.titleBarPartView.minimumHeight : 0) +
+			(this.isVisible(Parts.STATUSBAR_PART) ? this.statusBarPartView.minimumHeight : 0) +
+			(this.isVisible(Parts.PANEL_PART) && this.state.panel.position === Position.BOTTOM ? this.panelPartView.minimumHeight : 0);
+
+		const availableWidth = this.dimension.width - takenWidth;
+		const availableHeight = this.dimension.height - takenHeight;
+
+		return { width: availableWidth, height: availableHeight };
+	}
+
 	getWorkbenchContainer(): HTMLElement {
 		return this.parent;
 	}

src/vs/workbench/browser/parts/editor/editorPart.ts

@@ -140,7 +140,7 @@ export class EditorPart extends Part implements IEditorGroupsService, IEditorGro
 		@IThemeService themeService: IThemeService,
 		@IConfigurationService private readonly configurationService: IConfigurationService,
 		@IStorageService storageService: IStorageService,
-		@IWorkbenchLayoutService layoutService: IWorkbenchLayoutService
+		@IWorkbenchLayoutService private readonly layoutService: IWorkbenchLayoutService
 	) {
 		super(Parts.EDITOR_PART, { hasTitle: false }, themeService, storageService, layoutService);
 
@@ -780,9 +780,10 @@ export class EditorPart extends Part implements IEditorGroupsService, IEditorGro
 
 	//#region Part
 
-	get minimumWidth(): number { return this.centeredLayoutWidget.minimumWidth; }
+	// TODO @sbatten @joao find something better to prevent editor taking over #79897
+	get minimumWidth(): number { return Math.min(this.centeredLayoutWidget.minimumWidth, this.layoutService.getMaximumEditorDimensions().width); }
 	get maximumWidth(): number { return this.centeredLayoutWidget.maximumWidth; }
-	get minimumHeight(): number { return this.centeredLayoutWidget.minimumHeight; }
+	get minimumHeight(): number { return Math.min(this.centeredLayoutWidget.minimumHeight, this.layoutService.getMaximumEditorDimensions().height); }
 	get maximumHeight(): number { return this.centeredLayoutWidget.maximumHeight; }
 
 	readonly snap = true;

src/vs/workbench/services/layout/browser/layoutService.ts

@@ -144,6 +144,11 @@ export interface IWorkbenchLayoutService extends ILayoutService {
 	 */
 	setPanelPosition(position: Position): void;
 
+	/**
+	 * Gets the maximum possible size for editor.
+	 */
+	getMaximumEditorDimensions(): Dimension;
+
 	/**
 	 * Returns the element that is parent of the workbench element.
 	 */

src/vs/workbench/test/workbenchTestServices.ts

@@ -541,6 +541,8 @@ export class TestLayoutService implements IWorkbenchLayoutService {
 	public addClass(_clazz: string): void { }
 	public removeClass(_clazz: string): void { }
 
+	public getMaximumEditorDimensions(): Dimension { throw new Error('not implemented'); }
+
 	public getWorkbenchContainer(): HTMLElement { throw new Error('not implemented'); }
 	public getWorkbenchElement(): HTMLElement { throw new Error('not implemented'); }