category management

2022-03-07 17:34:09 +08:00
parent 49e4e46cdb
commit 46464e19dc
131 changed files with 3992 additions and 189 deletions
--- a/Billing.Shared/UI/ColorPicker.cs
+++ b/Billing.Shared/UI/ColorPicker.cs
@ -0,0 +1,137 @@
+using SkiaSharp;
+using SkiaSharp.Views.Forms;
+using System;
+
+using Xamarin.Forms;
+
+namespace Billing.UI
+{
+    public class ColorPicker : SKCanvasView
+    {
+        public static readonly BindableProperty ColorProperty = BindableProperty.Create(nameof(Color), typeof(Color), typeof(ColorPicker));
+
+        public Color Color
+        {
+            get => (Color)GetValue(ColorProperty);
+            set => SetValue(ColorProperty, value);
+        }
+
+        public event EventHandler<Color> ColorChanged;
+
+        private SKPoint? lastTouch;
+
+        public ColorPicker()
+        {
+            EnableTouchEvents = true;
+        }
+
+        protected override void OnPaintSurface(SKPaintSurfaceEventArgs e)
+        {
+            base.OnPaintSurface(e);
+            var skInfo = e.Info;
+            var skSurface = e.Surface;
+            var skCanvas = skSurface.Canvas;
+
+            var width = skInfo.Width;
+            var height = skInfo.Height;
+
+            skCanvas.Clear(SKColors.White);
+
+            using (var paint = new SKPaint())
+            {
+                paint.IsAntialias = true;
+                var colors = new SKColor[]
+                {
+                new SKColor(255, 0, 0),   // Red
+                new SKColor(255, 255, 0), // Yellow
+                new SKColor(0, 255, 0),   // Green (Lime)
+                new SKColor(0, 255, 255), // Aqua
+                new SKColor(0, 0, 255),   // Blue
+                new SKColor(255, 0, 255), // Fuchsia
+                new SKColor(255, 0, 0),   // Red
+                };
+
+                using var shader = SKShader.CreateLinearGradient(
+                    new SKPoint(0, 0),
+                    new SKPoint(width, 0),
+                    colors,
+                    null,
+                    SKShaderTileMode.Clamp);
+                paint.Shader = shader;
+                skCanvas.DrawPaint(paint);
+            }
+
+            using (var paint = new SKPaint())
+            {
+                paint.IsAntialias = true;
+                var colors = new SKColor[]
+                {
+                    SKColors.Transparent,
+                    SKColors.Black
+                };
+                using var shader = SKShader.CreateLinearGradient(
+                    new SKPoint(0, 0),
+                    new SKPoint(0, height),
+                    colors,
+                    null,
+                    SKShaderTileMode.Clamp);
+                paint.Shader = shader;
+                skCanvas.DrawPaint(paint);
+            }
+
+            if (lastTouch != null)
+            {
+                var touch = lastTouch.Value;
+                SKColor touchColor;
+                using (SKBitmap bitmap = new(skInfo))
+                {
+                    IntPtr dstPixels = bitmap.GetPixels();
+                    skSurface.ReadPixels(
+                        skInfo,
+                        dstPixels,
+                        skInfo.RowBytes,
+                        (int)touch.X, (int)touch.Y);
+                    touchColor = bitmap.GetPixel(0, 0);
+                }
+
+                using (SKPaint paintTouch = new())
+                {
+                    paintTouch.Style = SKPaintStyle.Fill;
+                    paintTouch.Color = SKColors.White;
+                    paintTouch.IsAntialias = true;
+
+                    skCanvas.DrawCircle(
+                        touch.X,
+                        touch.Y,
+                        18,
+                        paintTouch);
+
+                    paintTouch.Color = touchColor;
+                    skCanvas.DrawCircle(
+                        touch.X,
+                        touch.Y,
+                        12,
+                        paintTouch);
+                }
+
+                var color = touchColor.ToFormsColor();
+                Color = color;
+                ColorChanged?.Invoke(this, color);
+            }
+        }
+
+        protected override void OnTouch(SKTouchEventArgs e)
+        {
+            base.OnTouch(e);
+            lastTouch = e.Location;
+
+            var size = CanvasSize;
+            if ((e.Location.X > 0 && e.Location.X < size.Width) &&
+                (e.Location.Y > 0 && e.Location.Y < size.Height))
+            {
+                e.Handled = true;
+                InvalidateSurface();
+            }
+        }
+    }
+}