Starting work on moving GUI to event system (doesnt compile)

src/GUIStuff/Elements/ColorRectangleDisplay.cpp

@@ -0,0 +1,49 @@
+#include "ColorRectangleDisplay.hpp"
+
+namespace GUIStuff {
+
+ColorRectangleDisplay::ColorRectangleDisplay(GUIManager& gui): Element(gui) {}
+
+void ColorRectangleDisplay::layout(const std::function<SkColor4f()>& colorFunc) {
+    this->colorFunc = colorFunc;
+}
+
+void ColorRectangleDisplay::clay_draw(SkCanvas* canvas, UpdateInputData& io, Clay_RenderCommand* command, bool skiaAA) {
+    auto& bb = boundingBox.value();
+
+    SkColor4f color = colorFunc();
+    SkRect r = SkRect::MakeLTRB(bb.min.x(), bb.min.y(), bb.max.x(), bb.max.y());
+
+    if(color.fA == 1.0f) {
+        SkPaint p;
+        p.setColor4f(color);
+        p.setAntiAlias(skiaAA);
+        canvas->drawRect(r, p);
+    }
+    else {
+        canvas->save();
+        canvas->clipRect(r, skiaAA);
+        SkPaint alphaPaint;
+        alphaPaint.setShader(get_alpha_background_shader());
+        canvas->drawPaint(alphaPaint);
+        canvas->drawPaint(SkPaint{color});
+        canvas->restore();
+    }
+}
+
+sk_sp<SkShader> ColorRectangleDisplay::get_alpha_background_shader() {
+    if(!alphaBackgroundEffect) {
+        auto [effect, err] = SkRuntimeEffect::MakeForShader(SkString(alphaBackgroundSksl));
+        if(!err.isEmpty()) {
+            std::cout << "[ColorRectangleDisplay::get_alpha_background_shader] Alpha background shader construction error\n";
+            std::cout << err.c_str() << std::endl;
+            return nullptr;
+        }
+        else
+            alphaBackgroundEffect = effect;
+    }
+    SkRuntimeShaderBuilder builder(alphaBackgroundEffect);
+    return builder.makeShader();
+}
+
+}