Merge pull request #62 from nativescript-community/fix-ios-set-matrix

fix(ui-canvas): Proper iOS scale for bitmap cases

Author: farfromrefug

src/ui-canvas/canvas.ios.ts

@@ -1361,8 +1361,26 @@ export class Canvas implements ICanvas {
     mWidth: number;
     mHeight: number;
     mScale = 1;
+    mIsBitmap = false;
     view: WeakRef<CanvasView>;
 
+    constructor(imageOrWidth: ImageSource | UIImage | number, height?: number) {
+        let isBitmap = true;
+
+        if (imageOrWidth instanceof ImageSource) {
+            this.mCgContext = this._createContextFromImage(imageOrWidth.ios);
+        } else if (imageOrWidth instanceof UIImage) {
+            this.mCgContext = this._createContextFromImage(imageOrWidth);
+        } else if (imageOrWidth > 0 && height > 0) {
+            this.mCgContext = this._createContext(imageOrWidth, height);
+        } else {
+            isBitmap = false;
+        }
+
+        this.mIsBitmap = isBitmap;
+        // CGContextFillRect(this._cgContext);
+    }
+
     setBitmap(image) {
         // if (image instanceof ImageSource) {
         //     this._bitmap = image.android;
@@ -1454,7 +1472,7 @@ export class Canvas implements ICanvas {
     setMatrix(matrix: Matrix): void {
         // TODO: Find a better way to implement matrix set
         const ctx = this.ctx;
-        const density = Screen.mainScreen.scale;
+        const density = this.mIsBitmap ? 1 : Screen.mainScreen.scale;
         const currentMatrix = this.getMatrix();
         const invertedTransform = CGAffineTransformInvert(currentMatrix.mTransform);
         const scaleTransform = CGAffineTransformMake(density, 0, 0, -density, 0, density * this.mHeight);
@@ -1765,16 +1783,6 @@ export class Canvas implements ICanvas {
     getHeight() {
         return this.mHeight;
     }
-    constructor(imageOrWidth: ImageSource | UIImage | number, height?: number) {
-        if (imageOrWidth instanceof ImageSource) {
-            this.mCgContext = this._createContextFromImage(imageOrWidth.ios);
-        } else if (imageOrWidth instanceof UIImage) {
-            this.mCgContext = this._createContextFromImage(imageOrWidth);
-        } else if (imageOrWidth > 0 && height > 0) {
-            this.mCgContext = this._createContext(imageOrWidth, height);
-        }
-        // CGContextFillRect(this._cgContext);
-    }
 
     startApplyPaint(paint?: Paint, withFont = false) {
         this.save();