While there are plenty of examples demonstrating how to draw on a canvas, my specific problem involves loading a photo into memory, adding a shape to exact coordinates over the photo, and then drawing/scaling the photo onto a canvas. I'm unsure of where to begin with this task. Are there any libraries compatible with Ionic that can help achieve this?
Edit 1 - Progress update:
Private properties:
@ViewChild('mainCanvas') canvasEl: ElementRef;
private _CANVAS: any;
private _CONTEXT: any;
ionViewDidEnter():
this._CANVAS = this.canvasEl.nativeElement;
this._CONTEXT = this._CANVAS.getContext('2d');
updateCanvas():
var img = new Image();
const ctx = this._CONTEXT;
const canvas = this._CANVAS;
ctx.clearRect(0, 0, this._CANVAS.width, this._CANVAS.height);
ctx.fillStyle = "#ff0000";
img.onload = (() => {
img.width = img.width;
img.height = img.height;
canvas.width = img.width;
canvas.height = img.height;
ctx.drawImage(img, 0, 0);
ctx.lineWidth = 8;
ctx.strokeStyle = "#FF0000";
ctx.strokeRect(100, 100, 400, 400);
ctx.scale(0.5, 0.5); // this does nothing
});
img.src = (<any>window).Ionic.WebView.convertFileSrc(path);
Currently, the code successfully draws the photo and rectangle on the canvas. However, the resulting image is too large for the screen, so I need to scale the canvas after all drawing operations are done. Although I attempted to use ctx.scale, the canvas size remains unchanged regardless of the values I provide.