Take font size into consideration

android/src/main/java/com/swmansion/rnscreens/RNScreensPackage.kt

@@ -3,6 +3,7 @@ package com.swmansion.rnscreens
 import android.graphics.Color
 import android.view.View
 import android.view.View.MeasureSpec
+import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.Toolbar
 import androidx.coordinatorlayout.widget.CoordinatorLayout
@@ -88,6 +89,11 @@ class RNScreensPackage : TurboReactPackage() {
 
         val widthMeasureSpec = MeasureSpec.makeMeasureSpec(decorViewWidth, MeasureSpec.EXACTLY)
         val heightMeasureSpec = MeasureSpec.makeMeasureSpec(decorViewHeight, MeasureSpec.EXACTLY)
+
+        val textView = findTextViewInToolbar(toolbar)
+
+        textView?.takeIf { fontSize != -1 }?.let { it.textSize = fontSize.toFloat() }
+
         coordinatorLayout.measure(widthMeasureSpec, heightMeasureSpec)
         coordinatorLayout.layout(0, 0, decorViewWidth, decorViewHeight)
 
@@ -97,6 +103,18 @@ class RNScreensPackage : TurboReactPackage() {
         return height
     }
 
+    private fun findTextViewInToolbar(toolbar: Toolbar): TextView? {
+        for (i in 0 until toolbar.childCount) {
+            val view = toolbar.getChildAt(i)
+            if (view is TextView) {
+                if (view.text == toolbar.title) {
+                    return view
+                }
+            }
+        }
+        return null
+    }
+
     override fun createViewManagers(reactContext: ReactApplicationContext): List<ViewManager<*, *>> {
         WEAK_THIS = WeakReference(this)
 

android/src/main/java/com/swmansion/rnscreens/ScreenStackFragment.kt

@@ -232,6 +232,10 @@ class ScreenStackFragment : ScreenFragment, ScreenStackFragmentWrapper {
 
         override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
             super.onLayout(changed, l, t, r, b)
+            val headerNativelyMeasuredDimension = this.getChildAt(1).height
+            val tmp = headerNativelyMeasuredDimension
+            val tmpInDIP = PixelUtil.toDIPFromPixel(tmp.toFloat());
+            val tmp2 = tmpInDIP
         }
 
         override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {

apps/test-examples/src/TestHeader.tsx

@@ -22,9 +22,9 @@ export default function App(): JSX.Element {
           options={{
             headerShown: true,
             statusBarTranslucent: false,
-            // headerTitleStyle: {
-            //   fontSize: 64,
-            // }
+            headerTitleStyle: {
+              fontSize: 64,
+            }
           }}
         />
         <Stack.Screen

common/cpp/react/renderer/components/rnscreens/RNSScreenComponentDescriptor.h

@@ -3,6 +3,7 @@
 #include <fbjni/fbjni.h>
 #include <react/debug/react_native_assert.h>
 #include <react/renderer/core/ConcreteComponentDescriptor.h>
+#include <react/renderer/components/rnscreens/Props.h>
 #include "RNSScreenShadowNode.h"
 
 jint HEADER_HEIGHT = 0;
@@ -16,7 +17,18 @@ class RNSScreenComponentDescriptor final
  public:
   using ConcreteComponentDescriptor::ConcreteComponentDescriptor;
 
-  void adopt(ShadowNode &shadowNode) const override {
+
+  std::optional<std::reference_wrapper<const ShadowNode::Shared>> findHeaderConfigChild(const RNSScreenShadowNode &screenShadowNode) const {
+      for (const ShadowNode::Shared &child : screenShadowNode.getChildren()) {
+            if (std::strcmp(child->getComponentName(), "RNSScreenStackHeaderConfig") == 0) {
+                return {std::ref(child)};
+            }
+      }
+      return std::nullopt;
+//      return std::optional<std::reference_wrapper<const ShadowNode::Shared>>();
+  }
+
+    void adopt(ShadowNode &shadowNode) const override {
     react_native_assert(dynamic_cast<RNSScreenShadowNode *>(&shadowNode));
     auto &screenShadowNode = static_cast<RNSScreenShadowNode &>(shadowNode);
 
@@ -50,8 +62,16 @@ class RNSScreenComponentDescriptor final
       layoutableShadowNode.setPadding({.bottom = 0});
       layoutableShadowNode.setSize(
           Size{stateData.frameSize.width, stateData.frameSize.height});
-
     } else {
+        auto headerConfigChildOpt = findHeaderConfigChild(screenShadowNode);
+        int fontSize = -1;
+        if (headerConfigChildOpt) {
+            auto headerConfigChild = headerConfigChildOpt->get();
+            const auto &headerProps = *std::static_pointer_cast<const RNSScreenStackHeaderConfigProps>(headerConfigChild->getProps());
+            fontSize = headerProps.titleFontSize;
+//            headerConfigChild->getProps()
+        }
+
       JNIEnv *env = facebook::jni::Environment::current();
       if (env == nullptr) {
         // We can basically crash here
@@ -79,7 +99,8 @@ class RNSScreenComponentDescriptor final
       }
 
       jfloat headerHeight =
-          env->CallFloatMethod(packageInstance, computeDummyLayoutID, 24);
+          env->CallFloatMethod(packageInstance, computeDummyLayoutID, fontSize);
+
 
       layoutableShadowNode.setPadding(
           {.bottom = static_cast<float>(headerHeight)});