Text input improvements for Android

Author: eduardodoria

engine/core/System.cpp

@@ -59,7 +59,7 @@ sg_context_desc System::getSokolContext(){
     return {};
 }
 
-void System::showVirtualKeyboard(){
+void System::showVirtualKeyboard(std::wstring text){
 
 }
 

engine/core/System.h

@@ -36,7 +36,7 @@ namespace Supernova {
         virtual int getScreenWidth() = 0;
         virtual int getScreenHeight() = 0;
 
-        virtual void showVirtualKeyboard();
+        virtual void showVirtualKeyboard(std::wstring text = L"");
         virtual void hideVirtualKeyboard();
 
         virtual bool isFullscreen();

engine/core/subsystem/UISystem.cpp

@@ -1086,7 +1086,13 @@ void UISystem::eventOnPointerDown(float x, float y){
             }
 
             if (signature.test(scene->getComponentType<TextEditComponent>())){
-                System::instance().showVirtualKeyboard();
+                TextEditComponent& textedit = scene->getComponent<TextEditComponent>(entity);
+                TextComponent& text = scene->getComponent<TextComponent>(textedit.text);
+
+                std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> convert;
+                std::wstring utf16Text = convert.from_bytes(text.text);
+
+                System::instance().showVirtualKeyboard(utf16Text);
             }else{
                 System::instance().hideVirtualKeyboard();
             }

platform/android/NativeEngine.cpp

@@ -60,8 +60,7 @@ static NativeEngine *_singleton = NULL;
 // workaround for internal bug b/149866792
 static NativeEngineSavedState appState = {false};
 
-static std::string textInputBuffer;
-static bool firstInput;
+static std::wstring textInputBuffer;
 
 
 NativeEngine::NativeEngine(struct android_app *app) {
@@ -92,8 +91,7 @@ NativeEngine::NativeEngine(struct android_app *app) {
     // https://developer.android.com/reference/android/view/inputmethod/EditorInfo
     constexpr int IME_ACTION_NONE = 1;
     constexpr int IME_FLAG_NO_FULLSCREEN = 33554432;
-
-    //TODO: add support to input suggestions
+    
     GameActivity_setImeEditorInfo(app->activity, InputType_dot_TYPE_CLASS_TEXT, IME_ACTION_NONE, IME_FLAG_NO_FULLSCREEN);
 
     if (app->savedState != NULL) {
@@ -168,14 +166,16 @@ int NativeEngine::getScreenDensity(){
     return mScreenDensity;
 }
 
-void NativeEngine::showSoftInput(){
-    textInputBuffer = "";
-    firstInput = true;
+void NativeEngine::showSoftInput(std::wstring text){
+    textInputBuffer = text;
+
+    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> convert;
+    std::string strInputBuffer = convert.to_bytes(textInputBuffer);
 
-    mGameTextInputState.text_UTF8 = textInputBuffer.data();
-    mGameTextInputState.text_length = textInputBuffer.length();
-    mGameTextInputState.selection.start = textInputBuffer.length();
-    mGameTextInputState.selection.end = textInputBuffer.length();
+    mGameTextInputState.text_UTF8 = strInputBuffer.data();
+    mGameTextInputState.text_length = strInputBuffer.length();
+    mGameTextInputState.selection.start = strInputBuffer.length();
+    mGameTextInputState.selection.end = strInputBuffer.length();
     mGameTextInputState.composingRegion.start = -1;
     mGameTextInputState.composingRegion.end = -1;
 
@@ -248,20 +248,28 @@ void NativeEngine::gameLoop() {
         if (mApp->textInputState) {
                 GameActivity_getTextInputState(mApp->activity, [](void *context, const GameTextInputState *state) {
                     if (!context || !state) return;
-                    if (textInputBuffer.length() < state->text_length) {
-                        // text_length is different from utf16Text.length and state->(selection or composingRegion) with unicode chars
-                        if (state->text_length > 0) {
-                            std::wstring_convert<std::codecvt_utf8_utf16<wchar_t> > convert;
-                            std::wstring utf16Text = convert.from_bytes(state->text_UTF8);
-
-                            // getting only the last character
-                            Supernova::Engine::systemCharInput(utf16Text.back());
-                        }
-                    }else if (!firstInput){
+
+                    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> convert;
+                    std::wstring utf16Text = convert.from_bytes(state->text_UTF8);
+
+                    while (textInputBuffer.length() > utf16Text.length()){
+                        textInputBuffer.pop_back();
                         Supernova::Engine::systemCharInput('\b');
                     }
-                    textInputBuffer = std::string(state->text_UTF8, state->text_length);
-                    firstInput = false;
+
+                    int pos = 0;
+                    while (textInputBuffer[pos] == utf16Text[pos] and pos < textInputBuffer.length()){
+                        pos++;
+                    }
+
+                    for (int i = pos; i < textInputBuffer.length(); i++){
+                        Supernova::Engine::systemCharInput('\b');
+                    }
+                    for (int i = pos; i < utf16Text.length(); i++){
+                        Supernova::Engine::systemCharInput(utf16Text[i]);
+                    }
+                    textInputBuffer = utf16Text;
+
                 }, this);
             mApp->textInputState = 0;
         }

platform/android/NativeEngine.h

@@ -124,7 +124,7 @@ class NativeEngine {
     int getSurfHeight();
     int getScreenDensity();
 
-    void showSoftInput();
+    void showSoftInput(std::wstring text);
     void hideSoftInput();
 
     std::string getInternalDataPath();

platform/android/SupernovaAndroid.cpp

@@ -35,8 +35,8 @@ int SupernovaAndroid::getScreenHeight(){
     return NativeEngine::getInstance()->getSurfHeight();
 }
 
-void SupernovaAndroid::showVirtualKeyboard(){
-    NativeEngine::getInstance()->showSoftInput();
+void SupernovaAndroid::showVirtualKeyboard(std::wstring text){
+    NativeEngine::getInstance()->showSoftInput(text);
 }
 
 void SupernovaAndroid::hideVirtualKeyboard(){

platform/android/SupernovaAndroid.h

@@ -18,7 +18,7 @@ class SupernovaAndroid: public Supernova::System {
     virtual int getScreenWidth();
     virtual int getScreenHeight();
 
-	virtual void showVirtualKeyboard();
+	virtual void showVirtualKeyboard(std::wstring text);
 	virtual void hideVirtualKeyboard();
 
 	std::string getUserDataPath();

platform/apple/SupernovaApple.h

@@ -16,7 +16,7 @@ class SupernovaApple: public Supernova::System{
     virtual int getScreenWidth();
     virtual int getScreenHeight();
 
-    virtual void showVirtualKeyboard();
+    virtual void showVirtualKeyboard(std::wstring text);
     virtual void hideVirtualKeyboard();
 
     virtual std::string getAssetPath();

platform/apple/SupernovaApple.mm

@@ -56,7 +56,7 @@
     return Renderer.screenSize.height;
 }
 
-void SupernovaApple::showVirtualKeyboard(){
+void SupernovaApple::showVirtualKeyboard(std::wstring text){
 #if TARGET_OS_IPHONE
     [Renderer.view becomeFirstResponder];
 #endif