Add IWorkspaceManager.SwapActiveWorkspaceWithAdjacentMonitor (#661)

Adds a method to swap the active workspace with the workspace in the adjacent monitor.

Co-authored-by: Isaac Daly <[email protected]>

src/Whim.Tests/Workspace/WorkspaceManagerTests.cs

@@ -75,6 +75,10 @@ internal static void SetupMonitors(IContext ctx, IMonitor[] monitors, int active
 		if (monitors.Length > 0)
 		{
 			ctx.MonitorManager.ActiveMonitor.Returns(monitors[activeMonitorIndex]);
+
+			ctx.MonitorManager.GetPreviousMonitor(monitors[activeMonitorIndex])
+				.Returns(monitors[(activeMonitorIndex - 1).Mod(monitors.Length)]);
+			ctx.MonitorManager.GetNextMonitor(monitors[activeMonitorIndex]);
 		}
 	}
 
@@ -877,6 +881,95 @@ IWindow window
 		activatedWorkspace.Received(1).AddWindow(window);
 		Assert.Equal(workspaces[activatedWorkspaceIdx], workspaceManager.GetWorkspaceForWindow(window));
 	}
+	#endregion
+
+	#region SwapActiveWorkspaceWithAdjacentMonitor
+	[Theory]
+	[InlineAutoSubstituteData<WorkspaceManagerCustomization>(false)]
+	[InlineAutoSubstituteData<WorkspaceManagerCustomization>(true)]
+	internal void SwapActiveWorkspaceWithAdjacentMonitor_NoAdjacentMonitor(
+		bool reverse,
+		IContext ctx,
+		IInternalContext internalCtx
+	)
+	{
+		// Given there is only a single monitor and workspace...
+		IMonitor[] monitors = new[] { ctx.MonitorManager.ActiveMonitor };
+		SetupMonitors(ctx, monitors);
+		IWorkspace[] workspaces = CreateWorkspaces(1);
+		WorkspaceManagerTestWrapper workspaceManager = CreateSut(ctx, internalCtx, workspaces);
+
+		ActivateWorkspacesOnMonitors(workspaceManager, workspaces, monitors);
+
+		ClearWorkspaceReceivedCalls(workspaces);
+
+		// When SwapActiveWorkspaceWithAdjacentMonitor is called, then no event is raised
+		CustomAssert.DoesNotRaise<MonitorWorkspaceChangedEventArgs>(
+			h => workspaceManager.MonitorWorkspaceChanged += h,
+			h => workspaceManager.MonitorWorkspaceChanged -= h,
+			() => workspaceManager.SwapActiveWorkspaceWithAdjacentMonitor(reverse)
+		);
+	}
+
+	[Theory, AutoSubstituteData<WorkspaceManagerCustomization>]
+	internal void SwapActiveWorkspaceWithAdjacentMonitor_CouldNotFindWorkspace(
+		IContext ctx,
+		IInternalContext internalCtx,
+		IMonitor[] monitors
+	)
+	{
+		// Given a fake monitor is provided
+		IWorkspace[] workspaces = CreateWorkspaces(2);
+		WorkspaceManagerTestWrapper workspaceManager = CreateSut(ctx, internalCtx, workspaces);
+
+		ActivateWorkspacesOnMonitors(workspaceManager, workspaces, monitors);
+
+		ClearWorkspaceReceivedCalls(workspaces);
+
+		ctx.MonitorManager.GetNextMonitor(Arg.Any<IMonitor>()).Returns(Substitute.For<IMonitor>());
+
+		// When SwapActiveWorkspaceWithAdjacentMonitor is called, then no event is raised
+		CustomAssert.DoesNotRaise<MonitorWorkspaceChangedEventArgs>(
+			h => workspaceManager.MonitorWorkspaceChanged += h,
+			h => workspaceManager.MonitorWorkspaceChanged -= h,
+			() => workspaceManager.SwapActiveWorkspaceWithAdjacentMonitor(reverse: false)
+		);
+	}
+
+	[Theory, AutoSubstituteData<WorkspaceManagerCustomization>]
+	internal void SwapActiveWorkspaceWithAdjacentMonitor_Success(
+		IContext ctx,
+		IInternalContext internalCtx,
+		IMonitor[] monitors
+	)
+	{
+		// Given there are two workspaces and monitors
+		IWorkspace[] workspaces = CreateWorkspaces(2);
+		WorkspaceManagerTestWrapper workspaceManager = CreateSut(ctx, internalCtx, workspaces);
+
+		ActivateWorkspacesOnMonitors(workspaceManager, workspaces, monitors);
+
+		ClearWorkspaceReceivedCalls(workspaces);
+
+		ctx.MonitorManager.GetNextMonitor(Arg.Any<IMonitor>()).Returns(monitors[1]);
+
+		// When SwapActiveWorkspaceWithAdjacentMonitor is called, then an event is raised
+		var result = Assert.Raises<MonitorWorkspaceChangedEventArgs>(
+			h => workspaceManager.MonitorWorkspaceChanged += h,
+			h => workspaceManager.MonitorWorkspaceChanged -= h,
+			() => workspaceManager.SwapActiveWorkspaceWithAdjacentMonitor(reverse: false)
+		);
+
+		// Then the raised event will match the expected
+		Assert.Equal(monitors[0], result.Arguments.Monitor);
+		Assert.Equal(workspaces[1], result.Arguments.CurrentWorkspace);
+		Assert.Equal(workspaces[0], result.Arguments.PreviousWorkspace);
+
+		// The old workspace is deactivated, the new workspace is laid out, and the first window is
+		// focused.
+		workspaces[0].Received(1).DoLayout();
+		workspaces[1].Received(1).DoLayout();
+	}
 
 	#endregion
 

src/Whim/Workspace/IWorkspaceManager.cs

@@ -167,6 +167,14 @@ public interface IWorkspaceManager : IEnumerable<IWorkspace>, IDisposable
 	/// </param>
 	void MoveWindowToAdjacentWorkspace(IWindow? window = null, bool reverse = false, bool skipActive = false);
 
+	/// <summary>
+	/// Swap the currently active workspace with the one active on the next (or previous) monitor.
+	/// </summary>
+	/// <param name="reverse">
+	/// When <see langword="true"/>, swaps workspace with the previous monitor, otherwise with the next. Defaults to <see langword="false" />.
+	/// </param>
+	void SwapActiveWorkspaceWithAdjacentMonitor(bool reverse = false);
+
 	/// <summary>
 	/// Retrieves the monitor for the active workspace.
 	/// </summary>

src/Whim/Workspace/WorkspaceManager.cs

@@ -474,6 +474,31 @@ public void MoveWindowToAdjacentWorkspace(IWindow? window = null, bool reverse =
 		return null;
 	}
 
+	public void SwapActiveWorkspaceWithAdjacentMonitor(bool reverse = false)
+	{
+		// Get the next monitor.
+		IMonitor monitor = _context.MonitorManager.ActiveMonitor;
+		IMonitor nextMonitor = reverse
+			? _context.MonitorManager.GetPreviousMonitor(monitor)
+			: _context.MonitorManager.GetNextMonitor(monitor);
+
+		if (monitor.Equals(nextMonitor))
+		{
+			Logger.Error($"Monitor {monitor} is already the {(!reverse ? "next" : "previous")} monitor");
+			return;
+		}
+
+		// Get workspace on next monitor.
+		IWorkspace? nextWorkspace = GetWorkspaceForMonitor(nextMonitor);
+		if (nextWorkspace == null)
+		{
+			Logger.Error($"Monitor {nextMonitor} was not found to correspond to any workspace");
+			return;
+		}
+
+		Activate(nextWorkspace, monitor);
+	}
+
 	public IMonitor? GetMonitorForWorkspace(IWorkspace workspace)
 	{
 		Logger.Debug($"Getting monitor for active workspace {workspace}");