1
0
2023-11-12 19:09:24 -05:00

97 lines
3.6 KiB
C#

using Blazor.Extensions.Canvas.Canvas2D;
using Blazor.Extensions;
using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components;
using Microsoft.JSInterop;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json;
using System.Drawing;
using System.Threading;
using Microsoft.AspNetCore.Mvc.ApplicationModels;
namespace BlazorCanvas.Data;
// https://www.codeproject.com/Articles/5269947/Drawing-with-the-HTML-Canvas-Element-in-Blazor-Ser
public class CanvasService {
private Canvas2DContext? _currentCanvasContext;
private IJSRuntime _jsRuntime;
private CanvasCommand _lastCommand = new();
public CanvasService(IJSRuntime jsRuntime) {
_jsRuntime = jsRuntime;
}
public string currentColor { get; set; } = "Black";
public int pointSize { get; set; } = 1;
public bool snap { get; set; }
public ElementReference divCanvas { get; set; }
public BECanvasComponent myCanvas { get; set; } = new();
// TODO: Dessiner à partir des commandes de Franz.
public async void Draw(IEnumerable<CanvasCommand> lscommand) {
if (_currentCanvasContext is null) {
_currentCanvasContext = await myCanvas.CreateCanvas2DAsync();
await _currentCanvasContext.ClearRectAsync(0, 0, 1920, 1080);
}
await _currentCanvasContext.BeginBatchAsync();
foreach (CanvasCommand command in lscommand) {
await _currentCanvasContext.SetFillStyleAsync(command.Color);
await _currentCanvasContext.FillRectAsync(command.X, command.Y, command.PointSize, command.PointSize);
}
await _currentCanvasContext.EndBatchAsync();
}
public async void Draw(CanvasCommand command) {
if (_currentCanvasContext is null) {
_currentCanvasContext = await myCanvas.CreateCanvas2DAsync();
await _currentCanvasContext.ClearRectAsync(0, 0, 1920, 1080);
}
await _currentCanvasContext.SetFillStyleAsync(command.Color);
await _currentCanvasContext.FillRectAsync(command.X, command.Y, command.PointSize, command.PointSize);
}
public async void HandleMouse(MouseEventArgs eventArgs) {
double mouseX = 0, mouseY = 0;
if (eventArgs.Buttons == 0 || eventArgs.Buttons > 2)
return; // Rien faire si aucun bouton est appuyé ou si les deux boutons/ d'autres boutons sont appuyés.
if (divCanvas.Id?.Length > 0) {
string data = await _jsRuntime.InvokeAsync<string>("getDivCanvasOffsets",
new object[] { divCanvas });
string color = "White";
CanvasCommand command = new();
JObject? offsets = (JObject?)JsonConvert.DeserializeObject(data);
if (offsets is not null && offsets.HasValues) { // Translation entre le canvas et la souris.
mouseX = eventArgs.PageX - offsets.Value<double>("offsetLeft");
mouseY = eventArgs.PageY - offsets.Value<double>("offsetTop");
}
if (eventArgs.Buttons == 1) // Couleur si bouton gauche, blanc si bouton droit
color = currentColor;
if (snap) { // Magnétisme boboche.
mouseX -= mouseX % pointSize;
mouseY -= mouseY % pointSize;
}
command.X = mouseX;
command.Y = mouseY;
command.Color = color;
command.PointSize = pointSize;
if (command.Equals(_lastCommand))
return; // Pour pas spammer des commandes si c'est pas pertinent.
// TODO: Shipper les commandes à Franz.
Draw(command);
_lastCommand = command;
}
}
}