Paint增加保存，重写StartMenu的UI，修复部分渲染bug

Gui/Apps/Paint/Paint.cs

@@ -15,9 +15,13 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 using Cosmos.System;
+using Cosmos.System.Graphics;
 using CMLeonOS;
 using CMLeonOS.Gui.UILib;
+using CMLeonOS.Utils;
+using System;
 using System.Drawing;
+using System.IO;
 
 namespace CMLeonOS.Gui.Apps.Paint
 {
@@ -30,14 +34,24 @@ namespace CMLeonOS.Gui.Apps.Paint
         AppWindow window;
 
         Window canvas;
+        Button openButton;
+        Button saveButton;
+        Button saveAsButton;
 
         ToolBox toolBox;
 
         ColourPicker colourPicker;
+        FileBrowser fileBrowser;
 
         WindowManager wm = ProcessManager.GetProcess<WindowManager>();
 
         private bool down = false;
+        private const int sidePanelWidth = 128;
+        private const int topBarHeight = 40;
+        private const int topButtonWidth = 84;
+        private const int topButtonHeight = 24;
+        private const int topButtonGap = 8;
+        private string currentFilePath = string.Empty;
 
         internal Color SelectedColor { get; set; } = Color.Black;
 
@@ -54,6 +68,190 @@ namespace CMLeonOS.Gui.Apps.Paint
             down = true;
         }
 
+        private void ShowMessage(string title, string text)
+        {
+            MessageBox messageBox = new MessageBox(this, title, text);
+            messageBox.Show();
+        }
+
+        private void Relayout()
+        {
+            toolBox.MoveAndResize(0, 0, sidePanelWidth, window.Height);
+            colourPicker.MoveAndResize(window.Width - sidePanelWidth, 0, sidePanelWidth, window.Height);
+
+            int buttonsX = sidePanelWidth + 12;
+            openButton.MoveAndResize(buttonsX, 8, topButtonWidth, topButtonHeight);
+            saveButton.MoveAndResize(buttonsX + topButtonWidth + topButtonGap, 8, topButtonWidth, topButtonHeight);
+            saveAsButton.MoveAndResize(buttonsX + (topButtonWidth + topButtonGap) * 2, 8, topButtonWidth, topButtonHeight);
+            openButton.Render();
+            saveButton.Render();
+            saveAsButton.Render();
+
+            int canvasX = sidePanelWidth + 12;
+            int canvasY = topBarHeight + 8;
+            int canvasWidth = window.Width - sidePanelWidth * 2 - 24;
+            int canvasHeight = window.Height - canvasY - 12;
+            canvas.MoveAndResize(canvasX, canvasY, canvasWidth, canvasHeight);
+
+            if (canvasWidth > 0 && canvasHeight > 0)
+            {
+                canvas.DrawRectangle(0, 0, canvas.Width, canvas.Height, Color.Black);
+                wm.Update(canvas);
+            }
+        }
+
+        private void UpdateWindowTitle()
+        {
+            if (string.IsNullOrWhiteSpace(currentFilePath))
+            {
+                window.Title = "Paint";
+                return;
+            }
+
+            window.Title = $"Paint - {Path.GetFileName(currentFilePath)}";
+        }
+
+        private byte[] BuildBmpBytes()
+        {
+            int width = canvas.Width;
+            int height = canvas.Height;
+            int bytesPerPixel = 4;
+            int pixelDataSize = width * height * bytesPerPixel;
+            int fileSize = 54 + pixelDataSize;
+            byte[] bytes = new byte[fileSize];
+
+            bytes[0] = (byte)'B';
+            bytes[1] = (byte)'M';
+            BitConverter.GetBytes(fileSize).CopyTo(bytes, 2);
+            BitConverter.GetBytes(54).CopyTo(bytes, 10);
+            BitConverter.GetBytes(40).CopyTo(bytes, 14);
+            BitConverter.GetBytes(width).CopyTo(bytes, 18);
+            BitConverter.GetBytes(height).CopyTo(bytes, 22);
+            BitConverter.GetBytes((short)1).CopyTo(bytes, 26);
+            BitConverter.GetBytes((short)32).CopyTo(bytes, 28);
+            BitConverter.GetBytes(pixelDataSize).CopyTo(bytes, 34);
+
+            int offset = 54;
+            for (int y = height - 1; y >= 0; y--)
+            {
+                for (int x = 0; x < width; x++)
+                {
+                    Color color = canvas.GetPixel(x, y);
+                    bytes[offset++] = color.B;
+                    bytes[offset++] = color.G;
+                    bytes[offset++] = color.R;
+                    bytes[offset++] = color.A;
+                }
+            }
+
+            return bytes;
+        }
+
+        private void SaveCanvas(string path)
+        {
+            try
+            {
+                string sanitizedPath = PathUtil.Sanitize(path.Trim());
+                if (!sanitizedPath.EndsWith(".bmp", StringComparison.OrdinalIgnoreCase))
+                {
+                    sanitizedPath += ".bmp";
+                }
+
+                string directory = Path.GetDirectoryName(sanitizedPath);
+                if (!string.IsNullOrWhiteSpace(directory))
+                {
+                    Directory.CreateDirectory(directory);
+                }
+
+                File.WriteAllBytes(sanitizedPath, BuildBmpBytes());
+                currentFilePath = sanitizedPath;
+                UpdateWindowTitle();
+                ShowMessage("Paint", "Saved BMP successfully.");
+            }
+            catch (Exception ex)
+            {
+                ShowMessage("Paint", $"Save failed: {ex.Message}");
+            }
+        }
+
+        private void OpenImage(string path)
+        {
+            try
+            {
+                string sanitizedPath = PathUtil.Sanitize(path.Trim());
+                if (!File.Exists(sanitizedPath))
+                {
+                    ShowMessage("Paint", "File not found.");
+                    return;
+                }
+
+                if (!sanitizedPath.EndsWith(".bmp", StringComparison.OrdinalIgnoreCase))
+                {
+                    ShowMessage("Paint", "Only BMP files are supported.");
+                    return;
+                }
+
+                Bitmap bitmap = new Bitmap(File.ReadAllBytes(sanitizedPath));
+                canvas.Clear(Color.White);
+
+                int drawWidth = Math.Min(canvas.Width, (int)bitmap.Width);
+                int drawHeight = Math.Min(canvas.Height, (int)bitmap.Height);
+                for (int y = 0; y < drawHeight; y++)
+                {
+                    int rowOffset = y * (int)bitmap.Width;
+                    for (int x = 0; x < drawWidth; x++)
+                    {
+                        canvas.DrawPoint(x, y, Color.FromArgb(bitmap.RawData[rowOffset + x]));
+                    }
+                }
+
+                canvas.DrawRectangle(0, 0, canvas.Width, canvas.Height, Color.Black);
+                wm.Update(canvas);
+
+                currentFilePath = sanitizedPath;
+                UpdateWindowTitle();
+            }
+            catch (Exception ex)
+            {
+                ShowMessage("Paint", $"Open failed: {ex.Message}");
+            }
+        }
+
+        private void OpenClicked(int x, int y)
+        {
+            fileBrowser = new FileBrowser(this, wm, (string selectedPath) =>
+            {
+                if (!string.IsNullOrWhiteSpace(selectedPath))
+                {
+                    OpenImage(selectedPath);
+                }
+            }, selectDirectoryOnly: false);
+            fileBrowser.Show();
+        }
+
+        private void SaveAsClicked(int x, int y)
+        {
+            fileBrowser = new FileBrowser(this, wm, (string selectedPath) =>
+            {
+                if (!string.IsNullOrWhiteSpace(selectedPath))
+                {
+                    SaveCanvas(selectedPath);
+                }
+            }, selectDirectoryOnly: true);
+            fileBrowser.Show();
+        }
+
+        private void SaveClicked(int x, int y)
+        {
+            if (string.IsNullOrWhiteSpace(currentFilePath))
+            {
+                SaveAsClicked(x, y);
+                return;
+            }
+
+            SaveCanvas(currentFilePath);
+        }
+
         public override void Start()
         {
             base.Start();
@@ -61,22 +259,39 @@ namespace CMLeonOS.Gui.Apps.Paint
             window.Title = "Paint";
             window.Icon = AppManager.GetAppMetadata("Paint").Icon;
             window.Closing = TryStop;
+            window.UserResized = Relayout;
             window.Clear(Color.FromArgb(73, 73, 73));
             wm.AddWindow(window);
 
-            int canvasWidth = 384;
-            int canvasHeight = 256;
-            canvas = new Window(this, (window.Width / 2) - (canvasWidth / 2), (window.Height / 2) - (canvasHeight / 2), canvasWidth, canvasHeight);
+            canvas = new Window(this, 0, 0, 1, 1);
             canvas.RelativeTo = window;
             canvas.OnDown = CanvasDown;
             canvas.Clear(Color.White);
             wm.AddWindow(canvas);
 
-            toolBox = new ToolBox(this, 0, 0, 128, window.Height);
+            openButton = new Button(window, 0, 0, 1, 1);
+            openButton.Text = "Open";
+            openButton.OnClick = OpenClicked;
+            wm.AddWindow(openButton);
+
+            saveButton = new Button(window, 0, 0, 1, 1);
+            saveButton.Text = "Save";
+            saveButton.OnClick = SaveClicked;
+            wm.AddWindow(saveButton);
+
+            saveAsButton = new Button(window, 0, 0, 1, 1);
+            saveAsButton.Text = "Save As";
+            saveAsButton.OnClick = SaveAsClicked;
+            wm.AddWindow(saveAsButton);
+
+            toolBox = new ToolBox(this, 0, 0, sidePanelWidth, window.Height);
             toolBox.RelativeTo = window;
-            colourPicker = new ColourPicker(this, window.Width - 128, 0, 128, window.Height);
+            colourPicker = new ColourPicker(this, window.Width - sidePanelWidth, 0, sidePanelWidth, window.Height);
             colourPicker.RelativeTo = window;
 
+            UpdateWindowTitle();
+            Relayout();
+
             wm.Update(window);
         }