From 1377d34359aeb17f2490086b6f7bb928eeb808f9 Mon Sep 17 00:00:00 2001
From: Elias Aebi <eyelash@users.noreply.github.com>
Date: Mon, 2 Sep 2024 08:49:16 +0200
Subject: [PATCH] gral_window_show_context_menu

---
 demos/events.c   | 11 +++++++++++
 gral.h           |  4 ++++
 gral_linux.c     | 19 +++++++++++++++++++
 gral_macos.m     |  4 ++++
 gral_windows.cpp | 23 +++++++++++++++++++++++
 5 files changed, 61 insertions(+)

diff --git a/demos/events.c b/demos/events.c
index 99415ec..1dccee9 100644
--- a/demos/events.c
+++ b/demos/events.c
@@ -43,6 +43,17 @@ static void mouse_button_press(float x, float y, int button, int modifiers, void
 		gral_timer_delete(demo->timer);
 		demo->timer = 0;
 	}
+	if (button == GRAL_SECONDARY_MOUSE_BUTTON) {
+		static struct gral_menu_item items[] = {
+			{"First"},
+			{"Second"},
+			{"Third"},
+			{"-"},
+			{"Last"},
+			{NULL}
+		};
+		gral_window_show_context_menu(demo->window, x, y, items);
+	}
 }
 
 static void mouse_button_release(float x, float y, int button, void *user_data) {
diff --git a/gral.h b/gral.h
index 3b4d4d2..190e2dc 100644
--- a/gral.h
+++ b/gral.h
@@ -90,6 +90,9 @@ struct gral_window_interface {
 	void (*focus_enter)(void *user_data);
 	void (*focus_leave)(void *user_data);
 };
+struct gral_menu_item {
+	char const *text;
+};
 struct gral_timer;
 struct gral_file;
 struct gral_directory_watcher;
@@ -157,6 +160,7 @@ void gral_window_show_open_file_dialog(struct gral_window *window, void (*callba
 void gral_window_show_save_file_dialog(struct gral_window *window, void (*callback)(char const *file, void *user_data), void *user_data);
 void gral_window_clipboard_copy(struct gral_window *window, char const *text);
 void gral_window_clipboard_paste(struct gral_window *window, void (*callback)(char const *text, void *user_data), void *user_data);
+void gral_window_show_context_menu(struct gral_window *window, float x, float y, struct gral_menu_item *items);
 
 struct gral_timer *gral_timer_create(int milliseconds, void (*callback)(void *user_data), void *user_data);
 void gral_timer_delete(struct gral_timer *timer);
diff --git a/gral_linux.c b/gral_linux.c
index e35c5fc..8fb6354 100644
--- a/gral_linux.c
+++ b/gral_linux.c
@@ -638,6 +638,25 @@ void gral_window_clipboard_paste(struct gral_window *window, void (*callback)(ch
 	gtk_clipboard_request_text(clipboard, paste_callback, callback_data);
 }
 
+void gral_window_show_context_menu(struct gral_window *window, float x, float y, struct gral_menu_item *items) {
+	GtkWidget *area = gtk_bin_get_child(GTK_BIN(window));
+	GtkWidget *menu = gtk_menu_new();
+	gtk_menu_attach_to_widget(GTK_MENU(menu), area, NULL);
+	for (; items->text; ++items) {
+		GtkWidget *item;
+		if (items->text[0] == '-') {
+			item = gtk_separator_menu_item_new();
+		}
+		else {
+			item = gtk_menu_item_new_with_label(items->text);
+		}
+		gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);
+	}
+	gtk_widget_show_all(menu);
+	GdkRectangle rect = {x, y, 1, 1};
+	gtk_menu_popup_at_rect(GTK_MENU(menu), gtk_widget_get_window(area), &rect, GDK_GRAVITY_SOUTH_EAST, GDK_GRAVITY_NORTH_WEST, NULL);
+}
+
 typedef struct {
 	void (*callback)(void *user_data);
 	void *user_data;
diff --git a/gral_macos.m b/gral_macos.m
index bc0d5ec..0ac0574 100644
--- a/gral_macos.m
+++ b/gral_macos.m
@@ -667,6 +667,10 @@ void gral_window_clipboard_paste(struct gral_window *window, void (*callback)(ch
 	}
 }
 
+void gral_window_show_context_menu(struct gral_window *window, float x, float y, struct gral_menu_item *items) {
+	// TODO: implement
+}
+
 @interface TimerCallbackObject: NSObject {
 @public
 	void (*callback)(void *user_data);
diff --git a/gral_windows.cpp b/gral_windows.cpp
index 1c83f48..a349bf2 100644
--- a/gral_windows.cpp
+++ b/gral_windows.cpp
@@ -1054,6 +1054,29 @@ void gral_window_clipboard_paste(gral_window *window, void (*callback)(char cons
 	CloseClipboard();
 }
 
+void gral_window_show_context_menu(gral_window *window, float x, float y, gral_menu_item *items) {
+	HMENU menu = CreatePopupMenu();
+	for (; items->text; ++items) {
+		MENUITEMINFO item;
+		item.cbSize = sizeof(MENUITEMINFO);
+		item.fMask = 0;
+		if (items->text[0] == '-') {
+			AppendMenu(menu, MF_SEPARATOR, 0, NULL);
+		}
+		else {
+			item.fType = MFT_STRING;
+			AppendMenu(menu, MF_STRING, 0, utf8_to_utf16(items->text));
+		}
+		//InsertMenuItem(menu, );
+	}
+	POINT point;
+	point.x = (LONG)x;
+	point.y = (LONG)y;
+	ClientToScreen((HWND)window, &point);
+	TrackPopupMenuEx(menu, TPM_LEFTALIGN | TPM_TOPALIGN, point.x, point.y, (HWND)window, NULL);
+	DestroyMenu(menu);
+}
+
 static void CALLBACK timer_completion_routine(LPVOID lpArgToCompletionRoutine, DWORD dwTimerLowValue, DWORD dwTimerHighValue) {
 	gral_timer *timer = (gral_timer *)lpArgToCompletionRoutine;
 	timer->callback(timer->user_data);