feat: Support letterSpacing for RTL.

src/Context.ts

@@ -68,6 +68,7 @@ var COMMA = ',',
     'strokeText',
     'transform',
     'translate',
+    'trySetLetterSpacing',
   ];
 
 var CONTEXT_PROPERTIES = [
@@ -92,6 +93,11 @@ var CONTEXT_PROPERTIES = [
 ] as const;
 
 const traceArrMax = 100;
+
+interface CanvasRenderingContext2DFeatureDetection extends CanvasRenderingContext2D {
+  letterSpacing: string | undefined;
+}
+
 /**
  * Konva wrapper around native 2d canvas context. It has almost the same API of 2d context with some additional functions.
  * With core Konva shapes you don't need to use this object. But you will use it if you want to create
@@ -706,6 +712,21 @@ export class Context {
   translate(x: number, y: number) {
     this._context.translate(x, y);
   }
+  /**
+    * Set letterSpacing if supported by browser.
+    * @method
+    * @name Konva.Context#trySetLetterSpacing
+    * @returns true if successful, false if not supported.
+    */
+  trySetLetterSpacing(letterSpacing: number): boolean {
+    var context = this._context as CanvasRenderingContext2DFeatureDetection;
+    var letterSpacingSupported = 'letterSpacing' in context;
+
+    if (letterSpacingSupported) {
+      context.letterSpacing = letterSpacing + "px";
+    }
+    return letterSpacingSupported;
+  }
   _enableTrace() {
     var that = this,
       len = CONTEXT_METHODS.length,

src/shapes/Text.ts

@@ -57,6 +57,7 @@ var AUTO = 'auto',
   PX_SPACE = 'px ',
   SPACE = ' ',
   RIGHT = 'right',
+  RTL = 'rtl',
   WORD = 'word',
   CHAR = 'char',
   NONE = 'none',
@@ -213,6 +214,8 @@ export class Text extends Shape<TextConfig> {
 
     context.setAttr('textAlign', LEFT);
 
+    var letterSpacingSupported = context.trySetLetterSpacing(letterSpacing);
+
     // handle vertical alignment
     if (verticalAlign === MIDDLE) {
       alignY = (this.getHeight() - textArrLen * lineHeightPx - padding * 2) / 2;
@@ -288,7 +291,7 @@ export class Text extends Shape<TextConfig> {
         context.stroke();
         context.restore();
       }
-      if (letterSpacing !== 0 || align === JUSTIFY) {
+      if ((letterSpacing !== 0 && !letterSpacingSupported) || align === JUSTIFY) {
         //   var words = text.split(' ');
         spacesNumber = text.split(' ').length - 1;
         var array = stringToArray(text);