support for android screen rotation

tpecholt · Nov 6, 2023 · a9d46ce · a9d46ce
1 parent 07318a4
commit a9d46ce
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Showing 4 changed files with 37 additions and 7 deletions.
diff --git a/src/imrad.h b/src/imrad.h
@@ -74,8 +74,9 @@ struct CustomWidgetArgs
 struct IOUserData
 {
 	float dpiScale = 1;
-	float androidNavBarHeight = 0;
-	int imeType = 0;
+	ImVec2 displayRectMinOffset;
+	ImVec2 displayRectMaxOffset;
+	int requestedIMEType = 0;
 };
 
 //------------------------------------------------------------------------

diff --git a/src/node.cpp b/src/node.cpp
@@ -669,9 +669,10 @@ void TopWindow::Export(std::ostream& os, UIContext& ctx)
 	{
 		os << ctx.ind << "auto* ioUserData = (ImRad::IOUserData*)ImGui::GetIO().UserData;\n";
 		os << ctx.ind << "ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0);\n";
-		os << ctx.ind << "ImGui::SetNextWindowPos({ 0, 0 });\n";
-		os << ctx.ind << "ImGui::SetNextWindowSize({ ImGui::GetIO().DisplaySize.x, ImGui::GetIO().DisplaySize.y - ioUserData->androidNavBarHeight });"
-			<< " //{ " << size_x.to_arg(ctx.unit) << ", " << size_y.to_arg(ctx.unit) << " }\n";
+		os << ctx.ind << "ImGui::SetNextWindowPos(ioUserData->displayRectMinOffset);\n";
+		os << ctx.ind << "ImGui::SetNextWindowSize({ ImGui::GetIO().DisplaySize.x - ioUserData->displayRectMinOffset.x - ioUserData->displayRectMaxOffset.x, \n";
+		os << ctx.ind << "                           ImGui::GetIO().DisplaySize.y - ioUserData->displayRectMinOffset.y - ioUserData->displayRectMaxOffset.y });";
+		os << " //{ " << size_x.to_arg(ctx.unit) << ", " << size_y.to_arg(ctx.unit) << " }\n";
 		std::string fl = "ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoSavedSettings";
 		os << ctx.ind << "bool tmpOpen;\n";
 		os << ctx.ind << "if (ImGui::Begin(\"###" << ctx.codeGen->GetName() << "\", &tmpOpen, " << fl << "))\n";

diff --git a/template/MainActivity.java b/template/MainActivity.java
@@ -28,6 +28,7 @@ public class MainActivity extends NativeActivity {
     private EditText mEditText;
 
     private native void OnKeyboardShown(boolean b);
+    private native void OnScreenRotation(int deg);
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -102,6 +103,13 @@ else if (ev.getAction() == KeyEvent.ACTION_MULTIPLE) {
         return super.dispatchKeyEvent(ev);
     }
 
+    @Override
+    public void onConfigurationChanged(Configuration cfg) {
+        super.onConfigurationChanged(cfg);
+        int angle = 90 * getWindowManager().getDefaultDisplay().getRotation();
+        OnScreenRotation(angle);
+    }
+
     // JNI calls --------------------------------------------------
 
     public int getDpi() {

diff --git a/template/android-main.cpp b/template/android-main.cpp
@@ -24,6 +24,7 @@ static struct android_app*  g_App = nullptr;
 static bool                 g_Initialized = false;
 static char                 g_LogTag[] = "ImGuiExample";
 static std::string          g_IniFilename = "";
+static int                  g_NavBarHeight = 0;
 static ImRad::IOUserData    g_IOUserData;
 static int                  g_IMEType = 0;
 
@@ -48,6 +49,25 @@ Java_com_example_myapplication_MainActivity_OnKeyboardShown(JNIEnv *env, jobject
         g_IMEType = 0;
 }
 
+extern "C"
+JNIEXPORT void JNICALL
+Java_com_example_myapplication_MainActivity_OnScreenRotation(JNIEnv *env, jobject thiz, jint angle) {
+    switch (angle) {
+        case 0:
+            g_IOUserData.displayRectMinOffset = { 0, 0 };
+            g_IOUserData.displayRectMaxOffset = { 0, (float)g_NavBarHeight };
+            break;
+        case 90:
+            g_IOUserData.displayRectMinOffset = { 0, 0 };
+            g_IOUserData.displayRectMaxOffset = { (float)g_NavBarHeight, 0 };
+            break;
+        case 270:
+            g_IOUserData.displayRectMinOffset = { (float)g_NavBarHeight, 0 };
+            g_IOUserData.displayRectMaxOffset = { 0, 0 };
+            break;
+    }
+}
+
 // Main code
 static void handleAppCmd(struct android_app* app, int32_t appCmd)
 {
@@ -166,7 +186,6 @@ void Init(struct android_app* app)
     // Load ImRAD style including fonts:
     // ImRad::LoadStyle(fname, g_IOUserData.dpiScale);
     // Alternatively, setup Dear ImGui style
-
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
@@ -369,8 +388,9 @@ static void GetDisplayInfo()
         return;
 
     jint dpi = java_env->CallIntMethod(g_App->activity->clazz, method_id);
+    g_NavBarHeight = 48 * dpi / 160.0;
     g_IOUserData.dpiScale = dpi / 120.0; //relative to laptop screen DPI;
-    g_IOUserData.androidNavBarHeight = 48 * dpi / 160.0;
+    g_IOUserData.displayRectMaxOffset.y = g_NavBarHeight; //TODO: detect initial screen rotation
     ImGui::GetIO().UserData = &g_IOUserData;
 
     jni_return = java_vm->DetachCurrentThread();