Android: Add selection dialog (drop down/combo box) (#13814)

- The handling of IGUIComboBox uses the new setAndSendSelected() method.
- getDialogState() is now getInputDialogState() and returns the state of the input dialog.
- getLastDialogType() is added and returns current/last shown dialog's type.
- getInputDialogState() now returns an enum instead of int.
- getAndroidUIInput() now returns void instead of bool.
- New data types (enum) are added:
  (1) GameActivity.DialogType (Java) and porting::AndroidDialogType (C++)
  (2) GameActivity.DialogState (Java) and porting::AndroidDialogState (C++)
- When showing a text input dialog, there is no custom accept button text any more.
- showDialog()/showDialogUI() for text input is now showTextInputDialog()/showTextInputDialogUI().
- showInputDialog()/showDialogUI() for text input is now showTextInputDialog()/showTextInputDialogUI().
- getDialogValue()/getInputDialogValue() is now getDialogMessage()/getInputDialogMessage().


Co-authored-by: Gregor Parzefall <82708541+grorp@users.noreply.github.com>

android/app/src/main/java/net/minetest/minetest/GameActivity.java

@@ -51,8 +51,13 @@ public class GameActivity extends NativeActivity {
 		System.loadLibrary("minetest");
 	}
 
-	private int messageReturnCode = -1;
+	enum DialogType { TEXT_INPUT, SELECTION_INPUT }
+	enum DialogState { DIALOG_SHOWN, DIALOG_INPUTTED, DIALOG_CANCELED }
+
+	private DialogType lastDialogType = DialogType.TEXT_INPUT;
+	private DialogState inputDialogState = DialogState.DIALOG_CANCELED;
 	private String messageReturnValue = "";
+	private int selectionReturnValue = 0;
 
 	@Override
 	public void onCreate(Bundle savedInstanceState) {
@@ -85,11 +90,17 @@ public class GameActivity extends NativeActivity {
 		// Ignore the back press so Minetest can handle it
 	}
 
-	public void showDialog(String acceptButton, String hint, String current, int editType) {
+	public void showTextInputDialog(String hint, String current, int editType) {
-		runOnUiThread(() -> showDialogUI(hint, current, editType));
+		runOnUiThread(() -> showTextInputDialogUI(hint, current, editType));
 	}
 
-	private void showDialogUI(String hint, String current, int editType) {
+	public void showSelectionInputDialog(String[] optionList, int selectedIdx) {
+		runOnUiThread(() -> showSelectionInputDialogUI(optionList, selectedIdx));
+	}
+
+	private void showTextInputDialogUI(String hint, String current, int editType) {
+		lastDialogType = DialogType.TEXT_INPUT;
+		inputDialogState = DialogState.DIALOG_SHOWN;
 		final AlertDialog.Builder builder = new AlertDialog.Builder(this);
 		LinearLayout container = new LinearLayout(this);
 		container.setOrientation(LinearLayout.VERTICAL);
@@ -114,7 +125,7 @@ public class GameActivity extends NativeActivity {
 			// For multi-line, do not submit the text after pressing Enter key
 			if (keyCode == KeyEvent.KEYCODE_ENTER && editType != 1) {
 				imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
-				messageReturnCode = 0;
+				inputDialogState = DialogState.DIALOG_INPUTTED;
 				messageReturnValue = editText.getText().toString();
 				alertDialog.dismiss();
 				return true;
@@ -128,29 +139,55 @@ public class GameActivity extends NativeActivity {
 			doneButton.setText(R.string.ime_dialog_done);
 			doneButton.setOnClickListener((view -> {
 				imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
-				messageReturnCode = 0;
+				inputDialogState = DialogState.DIALOG_INPUTTED;
 				messageReturnValue = editText.getText().toString();
 				alertDialog.dismiss();
 			}));
 		}
 		alertDialog.setOnCancelListener(dialog -> {
 			getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
+			inputDialogState = DialogState.DIALOG_CANCELED;
 			messageReturnValue = current;
-			messageReturnCode = -1;
 		});
 		alertDialog.show();
 		editText.requestFocusTryShow();
 	}
 
-	public int getDialogState() {
+	public void showSelectionInputDialogUI(String[] optionList, int selectedIdx) {
-		return messageReturnCode;
+		lastDialogType = DialogType.SELECTION_INPUT;
+		inputDialogState = DialogState.DIALOG_SHOWN;
+		final AlertDialog.Builder builder = new AlertDialog.Builder(this);
+		builder.setSingleChoiceItems(optionList, selectedIdx, (dialog, selection) -> {
+			inputDialogState = DialogState.DIALOG_INPUTTED;
+			selectionReturnValue = selection;
+			dialog.dismiss();
+		});
+		builder.setOnCancelListener(dialog -> {
+			inputDialogState = DialogState.DIALOG_CANCELED;
+			selectionReturnValue = selectedIdx;
+		});
+		AlertDialog alertDialog = builder.create();
+		alertDialog.show();
 	}
 
-	public String getDialogValue() {
+	public int getLastDialogType() {
-		messageReturnCode = -1;
+		return lastDialogType.ordinal();
+	}
+
+	public int getInputDialogState() {
+		return inputDialogState.ordinal();
+	}
+
+	public String getDialogMessage() {
+		inputDialogState = DialogState.DIALOG_CANCELED;
 		return messageReturnValue;
 	}
 
+	public int getDialogSelection() {
+		inputDialogState = DialogState.DIALOG_CANCELED;
+		return selectionReturnValue;
+	}
+
 	public float getDensity() {
 		return getResources().getDisplayMetrics().density;
 	}

src/client/game.cpp

@@ -2277,7 +2277,7 @@ void Game::openConsole(float scale, const wchar_t *line)
 	assert(scale > 0.0f && scale <= 1.0f);
 
 #ifdef __ANDROID__
-	porting::showInputDialog(gettext("ok"), "", "", 2);
+	porting::showTextInputDialog("", "", 2);
 	m_android_chat_open = true;
 #else
 	if (gui_chat_console->isOpenInhibited())
@@ -2293,15 +2293,19 @@ void Game::openConsole(float scale, const wchar_t *line)
 #ifdef __ANDROID__
 void Game::handleAndroidChatInput()
 {
-	if (m_android_chat_open && porting::getInputDialogState() == 0) {
+	// It has to be a text input
-		std::string text = porting::getInputDialogValue();
+	if (m_android_chat_open && porting::getLastInputDialogType() == porting::TEXT_INPUT) {
+		porting::AndroidDialogState dialogState = porting::getInputDialogState();
+		if (dialogState == porting::DIALOG_INPUTTED) {
+			std::string text = porting::getInputDialogMessage();
 			client->typeChatMessage(utf8_to_wide(text));
+		}
+		if (dialogState != porting::DIALOG_SHOWN)
 			m_android_chat_open = false;
 	}
 }
 #endif
 
-
 void Game::toggleFreeMove()
 {
 	bool free_move = !g_settings->getBool("free_move");

src/gui/guiFormSpecMenu.cpp

@@ -3497,29 +3497,34 @@ void GUIFormSpecMenu::legacySortElements(std::list<IGUIElement *>::iterator from
 }
 
 #ifdef __ANDROID__
-bool GUIFormSpecMenu::getAndroidUIInput()
+void GUIFormSpecMenu::getAndroidUIInput()
 {
-	if (!hasAndroidUIInput())
+	porting::AndroidDialogState dialogState = getAndroidUIInputState();
-		return false;
+	if (dialogState == porting::DIALOG_SHOWN) {
+		return;
+	} else if (dialogState == porting::DIALOG_CANCELED) {
+		m_jni_field_name.clear();
+		return;
+	}
 
-	// still waiting
+	porting::AndroidDialogType dialog_type = porting::getLastInputDialogType();
-	if (porting::getInputDialogState() == -1)
-		return true;
 
 	std::string fieldname = m_jni_field_name;
 	m_jni_field_name.clear();
 
 	for (const FieldSpec &field : m_fields) {
 		if (field.fname != fieldname)
-			continue;
+			continue; // Iterate until found
 
 		IGUIElement *element = getElementFromId(field.fid, true);
 
-		if (!element || element->getType() != irr::gui::EGUIET_EDIT_BOX)
+		if (!element)
-			return false;
+			return;
 
+		auto element_type = element->getType();
+		if (dialog_type == porting::TEXT_INPUT && element_type == irr::gui::EGUIET_EDIT_BOX) {
 			gui::IGUIEditBox *editbox = (gui::IGUIEditBox *)element;
-		std::string text = porting::getInputDialogValue();
+			std::string text = porting::getInputDialogMessage();
 			editbox->setText(utf8_to_wide(text).c_str());
 
 			bool enter_after_edit = false;
@@ -3535,8 +3540,15 @@ bool GUIFormSpecMenu::getAndroidUIInput()
 				enter.GUIEvent.EventType = gui::EGET_EDITBOX_ENTER;
 				editbox->getParent()->OnEvent(enter);
 			}
+		} else if (dialog_type == porting::SELECTION_INPUT &&
+				element_type == irr::gui::EGUIET_COMBO_BOX) {
+			auto dropdown = (gui::IGUIComboBox *) element;
+			int selected = porting::getInputDialogSelection();
+			dropdown->setAndSendSelected(selected);
+		}
+
+		return; // Early-return after found
 	}
-	return false;
 }
 #endif
 

src/gui/guiFormSpecMenu.h

@@ -286,7 +286,7 @@ public:
 	core::rect<s32> getAbsoluteRect();
 
 #ifdef __ANDROID__
-	bool getAndroidUIInput();
+	void getAndroidUIInput();
 #endif
 
 protected:

src/gui/guiPasswordChange.cpp

@@ -264,14 +264,19 @@ std::string GUIPasswordChange::getNameByID(s32 id)
 }
 
 #ifdef __ANDROID__
-bool GUIPasswordChange::getAndroidUIInput()
+void GUIPasswordChange::getAndroidUIInput()
 {
-	if (!hasAndroidUIInput())
+	porting::AndroidDialogState dialogState = getAndroidUIInputState();
-		return false;
+	if (dialogState == porting::DIALOG_SHOWN) {
+		return;
+	} else if (dialogState == porting::DIALOG_CANCELED) {
+		m_jni_field_name.clear();
+		return;
+	}
 
-	// still waiting
+	// It has to be a text input
-	if (porting::getInputDialogState() == -1)
+	if (porting::getLastInputDialogType() != porting::TEXT_INPUT)
-		return true;
+		return;
 
 	gui::IGUIElement *e = nullptr;
 	if (m_jni_field_name == "old_password")
@@ -283,10 +288,10 @@ bool GUIPasswordChange::getAndroidUIInput()
 	m_jni_field_name.clear();
 
 	if (!e || e->getType() != irr::gui::EGUIET_EDIT_BOX)
-		return false;
+		return;
 
-	std::string text = porting::getInputDialogValue();
+	std::string text = porting::getInputDialogMessage();
 	e->setText(utf8_to_wide(text).c_str());
-	return false;
+	return;
 }
 #endif

src/gui/guiPasswordChange.h

@@ -45,7 +45,7 @@ public:
 
 	bool OnEvent(const SEvent &event);
 #ifdef __ANDROID__
-	bool getAndroidUIInput();
+	void getAndroidUIInput();
 #endif
 
 protected:

src/gui/modalMenu.cpp

@@ -268,11 +268,34 @@ bool GUIModalMenu::preprocessEvent(const SEvent &event)
 			if (((gui::IGUIEditBox *)hovered)->isPasswordBox())
 				type = 3;
 
-			porting::showInputDialog(gettext("OK"), "",
+			porting::showTextInputDialog("",
-				wide_to_utf8(((gui::IGUIEditBox *)hovered)->getText()), type);
+					wide_to_utf8(((gui::IGUIEditBox *) hovered)->getText()), type);
 			return retval;
 		}
 	}
+
+	if (event.EventType == EET_GUI_EVENT) {
+		if (event.GUIEvent.EventType == gui::EGET_LISTBOX_OPENED) {
+			gui::IGUIComboBox *dropdown = (gui::IGUIComboBox *) event.GUIEvent.Caller;
+
+			std::string field_name = getNameByID(dropdown->getID());
+			if (field_name.empty())
+				return false;
+
+			m_jni_field_name = field_name;
+
+			s32 selected_idx = dropdown->getSelected();
+			s32 option_size = dropdown->getItemCount();
+			std::string list_of_options[option_size];
+
+			for (s32 i = 0; i < option_size; i++) {
+				list_of_options[i] = wide_to_utf8(dropdown->getItem(i));
+			}
+
+			porting::showComboBoxDialog(list_of_options, option_size, selected_idx);
+			return true; // Prevent the Irrlicht dropdown from opening.
+		}
+	}
 #endif
 
 	// Convert touch events into mouse events.
@@ -347,22 +370,12 @@ bool GUIModalMenu::preprocessEvent(const SEvent &event)
 }
 
 #ifdef __ANDROID__
-bool GUIModalMenu::hasAndroidUIInput()
+porting::AndroidDialogState GUIModalMenu::getAndroidUIInputState()
 {
-	// no dialog shown
+	// No dialog is shown
 	if (m_jni_field_name.empty())
-		return false;
+		return porting::DIALOG_CANCELED;
 
-	// still waiting
+	return porting::getInputDialogState();
-	if (porting::getInputDialogState() == -1)
-		return true;
-
-	// no value abort dialog processing
-	if (porting::getInputDialogState() != 0) {
-		m_jni_field_name.clear();
-		return false;
-	}
-
-	return true;
 }
 #endif

src/gui/modalMenu.h

@@ -22,6 +22,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "irrlichttypes_extrabloated.h"
 #include "irr_ptr.h"
 #include "util/string.h"
+#ifdef __ANDROID__
+	#include <porting_android.h>
+#endif
 
 enum class PointerType {
 	Mouse,
@@ -59,8 +62,8 @@ public:
 	virtual bool OnEvent(const SEvent &event) { return false; };
 	virtual bool pausesGame() { return false; } // Used for pause menu
 #ifdef __ANDROID__
-	virtual bool getAndroidUIInput() { return false; }
+	virtual void getAndroidUIInput() {};
-	bool hasAndroidUIInput();
+	porting::AndroidDialogState getAndroidUIInputState();
 #endif
 
 	PointerType getPointerType() { return m_pointer_type; };

src/porting_android.cpp

@@ -165,22 +165,41 @@ bool setSystemPaths()
 	return true;
 }
 
-void showInputDialog(const std::string &acceptButton, const std::string &hint,
+void showTextInputDialog(const std::string &hint, const std::string &current, int editType)
-		const std::string &current, int editType)
 {
-	jmethodID showdialog = jnienv->GetMethodID(nativeActivity, "showDialog",
+	jmethodID showdialog = jnienv->GetMethodID(nativeActivity, "showTextInputDialog",
-		"(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;I)V");
+			"(Ljava/lang/String;Ljava/lang/String;I)V");
 
 	FATAL_ERROR_IF(showdialog == nullptr,
-		"porting::showInputDialog unable to find Java showDialog method");
+			"porting::showTextInputDialog unable to find Java showTextInputDialog method");
 
-	jstring jacceptButton = jnienv->NewStringUTF(acceptButton.c_str());
 	jstring jhint         = jnienv->NewStringUTF(hint.c_str());
 	jstring jcurrent      = jnienv->NewStringUTF(current.c_str());
 	jint    jeditType     = editType;
 
 	jnienv->CallVoidMethod(app_global->activity->clazz, showdialog,
-			jacceptButton, jhint, jcurrent, jeditType);
+			jhint, jcurrent, jeditType);
+}
+
+void showComboBoxDialog(const std::string optionList[], s32 listSize, s32 selectedIdx)
+{
+	jmethodID showdialog = jnienv->GetMethodID(nativeActivity, "showSelectionInputDialog",
+			"([Ljava/lang/String;I)V");
+
+	FATAL_ERROR_IF(showdialog == nullptr,
+			"porting::showComboBoxDialog unable to find Java showSelectionInputDialog method");
+
+	jclass       jStringClass = jnienv->FindClass("java/lang/String");
+	jobjectArray jOptionList  = jnienv->NewObjectArray(listSize, jStringClass, NULL);
+	jint         jselectedIdx = selectedIdx;
+
+	for (s32 i = 0; i < listSize; i ++) {
+		jnienv->SetObjectArrayElement(jOptionList, i,
+				jnienv->NewStringUTF(optionList[i].c_str()));
+	}
+
+	jnienv->CallVoidMethod(app_global->activity->clazz, showdialog, jOptionList,
+			jselectedIdx);
 }
 
 void openURIAndroid(const char *url)
@@ -207,30 +226,53 @@ void shareFileAndroid(const std::string &path)
 	jnienv->CallVoidMethod(app_global->activity->clazz, url_open, jurl);
 }
 
-int getInputDialogState()
+AndroidDialogType getLastInputDialogType()
 {
-	jmethodID dialogstate = jnienv->GetMethodID(nativeActivity,
+	jmethodID lastdialogtype = jnienv->GetMethodID(nativeActivity,
-			"getDialogState", "()I");
+			"getLastDialogType", "()I");
 
-	FATAL_ERROR_IF(dialogstate == nullptr,
+	FATAL_ERROR_IF(lastdialogtype == nullptr,
-		"porting::getInputDialogState unable to find Java getDialogState method");
+			"porting::getLastInputDialogType unable to find Java getLastDialogType method");
 
-	return jnienv->CallIntMethod(app_global->activity->clazz, dialogstate);
+	int dialogType = jnienv->CallIntMethod(app_global->activity->clazz, lastdialogtype);
+	return static_cast<AndroidDialogType>(dialogType);
 }
 
-std::string getInputDialogValue()
+AndroidDialogState getInputDialogState()
+{
+	jmethodID inputdialogstate = jnienv->GetMethodID(nativeActivity,
+			"getInputDialogState", "()I");
+
+	FATAL_ERROR_IF(inputdialogstate == nullptr,
+			"porting::getInputDialogState unable to find Java getInputDialogState method");
+
+	int dialogState = jnienv->CallIntMethod(app_global->activity->clazz, inputdialogstate);
+	return static_cast<AndroidDialogState>(dialogState);
+}
+
+std::string getInputDialogMessage()
 {
 	jmethodID dialogvalue = jnienv->GetMethodID(nativeActivity,
-			"getDialogValue", "()Ljava/lang/String;");
+			"getDialogMessage", "()Ljava/lang/String;");
 
 	FATAL_ERROR_IF(dialogvalue == nullptr,
-		"porting::getInputDialogValue unable to find Java getDialogValue method");
+			"porting::getInputDialogMessage unable to find Java getDialogMessage method");
 
 	jobject result = jnienv->CallObjectMethod(app_global->activity->clazz,
 			dialogvalue);
 	return readJavaString((jstring) result);
 }
 
+int getInputDialogSelection()
+{
+	jmethodID dialogvalue = jnienv->GetMethodID(nativeActivity, "getDialogSelection", "()I");
+
+	FATAL_ERROR_IF(dialogvalue == nullptr,
+			"porting::getInputDialogSelection unable to find Java getDialogSelection method");
+
+	return jnienv->CallIntMethod(app_global->activity->clazz, dialogvalue);
+}
+
 #ifndef SERVER
 float getDisplayDensity()
 {

src/porting_android.h

@@ -20,7 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #pragma once
 
 #ifndef __ANDROID__
-#error this include has to be included on android port only!
+#error This header has to be included on Android port only!
 #endif
 
 #include <jni.h>
@@ -30,22 +30,28 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <string>
 
 namespace porting {
-// java app
+// Java app
 extern android_app *app_global;
 
-// java <-> c++ interaction interface
+// Java <-> C++ interaction interface
 extern JNIEnv *jnienv;
 
 /**
- * show text input dialog in java
+ * Show a text input dialog in Java
- * @param acceptButton text to display on accept button
+ * @param hint Hint to be shown
- * @param hint hint to show
+ * @param current Initial value to be displayed
- * @param current initial value to display
+ * @param editType Type of the text field
- * @param editType type of texfield
+ * (1 = multi-line text input; 2 = single-line text input; 3 = password field)
- * (1==multiline text input; 2==single line text input; 3=password field)
  */
-void showInputDialog(const std::string &acceptButton,
+void showTextInputDialog(const std::string &hint, const std::string &current, int editType);
-					const std::string &hint, const std::string &current, int editType);
+
+/**
+ * Show a selection dialog in Java
+ * @param optionList The list of options
+ * @param listSize Size of the list
+ * @param selectedIdx Selected index
+ */
+void showComboBoxDialog(const std::string optionList[], s32 listSize, s32 selectedIdx);
 
 /**
  * Opens a share intent to the file at path
@@ -54,17 +60,48 @@ void showInputDialog(const std::string &acceptButton,
  */
 void shareFileAndroid(const std::string &path);
 
-/**
+/*
- * WORKAROUND for not working callbacks from java -> c++
+ * Types of Android input dialog:
- * get current state of input dialog
+ * 1. Text input (single/multi-line text and password field)
+ * 2. Selection input (combo box)
  */
-int getInputDialogState();
+enum AndroidDialogType { TEXT_INPUT, SELECTION_INPUT };
 
-/**
+/*
- * WORKAROUND for not working callbacks from java -> c++
+ * WORKAROUND for not working callbacks from Java -> C++
- * get text in current input dialog
+ * Get the type of the last input dialog
  */
-std::string getInputDialogValue();
+AndroidDialogType getLastInputDialogType();
+
+/*
+ * States of Android input dialog:
+ * 1. The dialog is currently shown.
+ * 2. The dialog has its input sent.
+ * 3. The dialog is canceled/dismissed.
+ */
+enum AndroidDialogState { DIALOG_SHOWN, DIALOG_INPUTTED, DIALOG_CANCELED };
+
+/*
+ * WORKAROUND for not working callbacks from Java -> C++
+ * Get the state of the input dialog
+ */
+AndroidDialogState getInputDialogState();
+
+/*
+ * WORKAROUND for not working callbacks from Java -> C++
+ * Get the text in the current/last input dialog
+ * This function clears the dialog state (set to canceled). Make sure to save
+ * the dialog state before calling this function.
+ */
+std::string getInputDialogMessage();
+
+/*
+ * WORKAROUND for not working callbacks from Java -> C++
+ * Get the selection in the current/last input dialog
+ * This function clears the dialog state (set to canceled). Make sure to save
+ * the dialog state before calling this function.
+ */
+int getInputDialogSelection();
 
 #ifndef SERVER
 float getDisplayDensity();