Add TextStyleInterface.hpp -> Will be inherited by all text-drawing widgets, to apply style cohesively. Other StyleInterface classes are being devised.

include/JUI/Mixins/TextStyleInterface.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+namespace JUI {
+    // TODO: Observe and design all the base interfaces for various style categories.
+
+    /// Defines interface for widgets with textual elements which are to be styled as a group.
+    class TextStyleInterface {
+    public:
+        virtual ~TextStyleInterface() = default;
+
+        virtual JGL::Font Font() const = 0;
+        virtual int TextSize() const = 0;
+        virtual Color4 TextColor() const = 0;
+        virtual bool WordWrap() const = 0;
+
+        virtual void Font(const JGL::Font& value) = 0;
+        virtual void TextSize(int value) = 0;
+        virtual void TextColor(const Color4& color) = 0;
+    };
+}