chore: add SizedFrame for window sizing (#54)

Author: deansheather

Diff for: App/Controls/SizedFrame.cs

@@ -0,0 +1,68 @@
+using System;
+using Windows.Foundation;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+
+namespace Coder.Desktop.App.Controls;
+
+public class SizedFrameEventArgs : EventArgs
+{
+    public Size NewSize { get; init; }
+}
+
+/// <summary>
+///     SizedFrame extends Frame by adding a SizeChanged event, which will be triggered when:
+///       - The contained Page's content's size changes
+///       - We switch to a different page.
+///
+///     Sadly this is necessary because Window.Content.SizeChanged doesn't trigger when the Page's content changes.
+/// </summary>
+public class SizedFrame : Frame
+{
+    public delegate void SizeChangeDelegate(object sender, SizedFrameEventArgs e);
+
+    public new event SizeChangeDelegate? SizeChanged;
+
+    private Size _lastSize;
+
+    public void SetPage(Page page)
+    {
+        if (ReferenceEquals(page, Content)) return;
+
+        // Set the new event listener.
+        if (page.Content is not FrameworkElement newElement)
+            throw new Exception("Failed to get Page.Content as FrameworkElement on SizedFrame navigation");
+        newElement.SizeChanged += Content_SizeChanged;
+
+        // Unset the previous event listener.
+        if (Content is Page { Content: FrameworkElement oldElement })
+            oldElement.SizeChanged -= Content_SizeChanged;
+
+        // We don't use RootFrame.Navigate here because it doesn't let you
+        // instantiate the page yourself. We also don't need forwards/backwards
+        // capabilities.
+        Content = page;
+
+        // Fire an event.
+        Content_SizeChanged(newElement, null);
+    }
+
+    public Size GetContentSize()
+    {
+        if (Content is not Page { Content: FrameworkElement frameworkElement })
+            throw new Exception("Failed to get Content as FrameworkElement for SizedFrame");
+
+        frameworkElement.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
+        return new Size(frameworkElement.ActualWidth, frameworkElement.ActualHeight);
+    }
+
+    private void Content_SizeChanged(object sender, SizeChangedEventArgs? _)
+    {
+        var size = GetContentSize();
+        if (size == _lastSize) return;
+        _lastSize = size;
+
+        var args = new SizedFrameEventArgs { NewSize = size };
+        SizeChanged?.Invoke(this, args);
+    }
+}

Diff for: App/Views/SignInWindow.xaml

@@ -4,6 +4,7 @@
     x:Class="Coder.Desktop.App.Views.SignInWindow"
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:Coder.Desktop.App.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d"
@@ -13,5 +14,5 @@
         <DesktopAcrylicBackdrop />
     </Window.SystemBackdrop>
 
-    <Frame x:Name="RootFrame" />
+    <controls:SizedFrame x:Name="RootFrame" />
 </Window>

Diff for: App/Views/SignInWindow.xaml.cs

@@ -1,49 +1,72 @@
+using System;
 using Windows.Graphics;
+using Coder.Desktop.App.Controls;
 using Coder.Desktop.App.ViewModels;
 using Coder.Desktop.App.Views.Pages;
 using Microsoft.UI.Windowing;
 using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Media;
 
 namespace Coder.Desktop.App.Views;
 
 /// <summary>
-///     The dialog window to allow the user to sign into their Coder server.
+///     The dialog window to allow the user to sign in to their Coder server.
 /// </summary>
 public sealed partial class SignInWindow : Window
 {
-    private const double WIDTH = 600.0;
-    private const double HEIGHT = 300.0;
+    private const double WIDTH = 500.0;
 
     private readonly SignInUrlPage _signInUrlPage;
     private readonly SignInTokenPage _signInTokenPage;
 
     public SignInWindow(SignInViewModel viewModel)
     {
         InitializeComponent();
+        SystemBackdrop = new DesktopAcrylicBackdrop();
+        RootFrame.SizeChanged += RootFrame_SizeChanged;
+
         _signInUrlPage = new SignInUrlPage(this, viewModel);
         _signInTokenPage = new SignInTokenPage(this, viewModel);
 
+        // Prevent the window from being resized.
+        if (AppWindow.Presenter is not OverlappedPresenter presenter)
+            throw new Exception("Failed to get OverlappedPresenter for window");
+        presenter.IsMaximizable = false;
+        presenter.IsResizable = false;
+
         NavigateToUrlPage();
         ResizeWindow();
         MoveWindowToCenterOfDisplay();
     }
 
     public void NavigateToTokenPage()
     {
-        RootFrame.Content = _signInTokenPage;
+        RootFrame.SetPage(_signInTokenPage);
     }
 
     public void NavigateToUrlPage()
     {
-        RootFrame.Content = _signInUrlPage;
+        RootFrame.SetPage(_signInUrlPage);
+    }
+
+    private void RootFrame_SizeChanged(object sender, SizedFrameEventArgs e)
+    {
+        ResizeWindow(e.NewSize.Height);
     }
 
     private void ResizeWindow()
     {
+        ResizeWindow(RootFrame.GetContentSize().Height);
+    }
+
+    private void ResizeWindow(double height)
+    {
+        if (height <= 0) height = 100; // will be resolved next frame typically
+
         var scale = DisplayScale.WindowScale(this);
-        var height = (int)(HEIGHT * scale);
-        var width = (int)(WIDTH * scale);
-        AppWindow.Resize(new SizeInt32(width, height));
+        var newWidth = (int)(WIDTH * scale);
+        var newHeight = (int)(height * scale);
+        AppWindow.ResizeClient(new SizeInt32(newWidth, newHeight));
     }
 
     private void MoveWindowToCenterOfDisplay()

Diff for: App/Views/TrayWindow.xaml

@@ -19,6 +19,6 @@
         <controls:TrayIcon x:Name="TrayIcon" />
 
         <!-- This is where the current Page is displayed -->
-        <Frame x:Name="RootFrame" />
+        <controls:SizedFrame x:Name="RootFrame" />
     </Grid>
 </Window>

Diff for: App/Views/TrayWindow.xaml.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Runtime.InteropServices;
-using Windows.Foundation;
 using Windows.Graphics;
 using Windows.System;
 using Windows.UI.Core;
+using Coder.Desktop.App.Controls;
 using Coder.Desktop.App.Models;
 using Coder.Desktop.App.Services;
 using Coder.Desktop.App.Views.Pages;
@@ -48,6 +48,7 @@ public TrayWindow(IRpcController rpcController, ICredentialManager credentialMan
         AppWindow.Hide();
         SystemBackdrop = new DesktopAcrylicBackdrop();
         Activated += Window_Activated;
+        RootFrame.SizeChanged += RootFrame_SizeChanged;
 
         rpcController.StateChanged += RpcController_StateChanged;
         credentialManager.CredentialsChanged += CredentialManager_CredentialsChanged;
@@ -120,55 +121,31 @@ public void SetRootFrame(Page page)
             return;
         }
 
-        if (ReferenceEquals(page, RootFrame.Content)) return;
-
-        if (page.Content is not FrameworkElement newElement)
-            throw new Exception("Failed to get Page.Content as FrameworkElement on RootFrame navigation");
-        newElement.SizeChanged += Content_SizeChanged;
-
-        // Unset the previous event listener.
-        if (RootFrame.Content is Page { Content: FrameworkElement oldElement })
-            oldElement.SizeChanged -= Content_SizeChanged;
-
-        // Swap them out and reconfigure the window.
-        // We don't use RootFrame.Navigate here because it doesn't let you
-        // instantiate the page yourself. We also don't need forwards/backwards
-        // capabilities.
-        RootFrame.Content = page;
-        ResizeWindow();
-        MoveWindow();
+        RootFrame.SetPage(page);
     }
 
-    private void Content_SizeChanged(object sender, SizeChangedEventArgs e)
+    private void RootFrame_SizeChanged(object sender, SizedFrameEventArgs e)
     {
-        ResizeWindow();
+        ResizeWindow(e.NewSize.Height);
         MoveWindow();
     }
 
     private void ResizeWindow()
     {
-        if (RootFrame.Content is not Page { Content: FrameworkElement frameworkElement })
-            throw new Exception("Failed to get Content as FrameworkElement for window");
-
-        // Measure the desired size of the content
-        frameworkElement.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
-
-        // Adjust the AppWindow size
-        var scale = GetDisplayScale();
-        var height = (int)(frameworkElement.ActualHeight * scale);
-        var width = (int)(WIDTH * scale);
-        AppWindow.Resize(new SizeInt32(width, height));
+        ResizeWindow(RootFrame.GetContentSize().Height);
     }
 
-    private double GetDisplayScale()
+    private void ResizeWindow(double height)
     {
-        var hwnd = WindowNative.GetWindowHandle(this);
-        var dpi = NativeApi.GetDpiForWindow(hwnd);
-        if (dpi == 0) return 1; // assume scale of 1
-        return dpi / 96.0; // 96 DPI == 1
+        if (height <= 0) height = 100; // will be resolved next frame typically
+
+        var scale = DisplayScale.WindowScale(this);
+        var newWidth = (int)(WIDTH * scale);
+        var newHeight = (int)(height * scale);
+        AppWindow.Resize(new SizeInt32(newWidth, newHeight));
     }
 
-    public void MoveResizeAndActivate()
+    private void MoveResizeAndActivate()
     {
         SaveCursorPos();
         ResizeWindow();
@@ -268,9 +245,6 @@ public static class NativeApi
         [DllImport("user32.dll")]
         public static extern bool SetForegroundWindow(IntPtr hwnd);
 
-        [DllImport("user32.dll")]
-        public static extern int GetDpiForWindow(IntPtr hwnd);
-
         public struct POINT
         {
             public int X;