PopupMenu rework and enhancements

Many scrolling behaviour improvements and the ability to limit popup size.

doc/classes/PopupMenu.xml

@@ -478,6 +478,9 @@
 		<member name="hide_on_state_item_selection" type="bool" setter="set_hide_on_state_item_selection" getter="is_hide_on_state_item_selection" default="false">
 			If [code]true[/code], hides the [PopupMenu] when a state item is selected.
 		</member>
+		<member name="max_height" type="float" setter="set_max_height" getter="get_max_height" default="0.0">
+			If non-zero, the [code]PopupMenu[/code] will be resized vertically to that maximum value, showing a scrollbar if the content doesn't fit.
+		</member>
 		<member name="submenu_popup_delay" type="float" setter="set_submenu_popup_delay" getter="get_submenu_popup_delay" default="0.3">
 			Sets the delay time in seconds for the submenu item to popup on mouse hovering. If the popup menu is added as a child of another (acting as a submenu), it will inherit the delay time of the parent menu item.
 		</member>

scene/gui/popup_menu.h

@@ -31,7 +31,10 @@
 #ifndef POPUP_MENU_H
 #define POPUP_MENU_H
 
+#include "scene/gui/margin_container.h"
 #include "scene/gui/popup.h"
+#include "scene/gui/scroll_container.h"
+#include "scene/gui/shortcut.h"
 
 class PopupMenu : public Popup {
 	GDCLASS(PopupMenu, Popup);
@@ -56,11 +59,17 @@ class PopupMenu : public Popup {
 		String tooltip;
 		uint32_t accel;
 		int _ofs_cache;
+		int _height_cache;
 		int h_ofs;
 		Ref<ShortCut> shortcut;
 		bool shortcut_is_global;
 		bool shortcut_is_disabled;
 
+		// Returns (0,0) if icon is null.
+		Size2 get_icon_size() const {
+			return icon.is_null() ? Size2() : icon->get_size();
+		}
+
 		Item() {
 			checked = false;
 			checkable_type = CHECKABLE_TYPE_NONE;
@@ -70,6 +79,7 @@ class PopupMenu : public Popup {
 			accel = 0;
 			disabled = false;
 			_ofs_cache = 0;
+			_height_cache = 0;
 			h_ofs = 0;
 			shortcut_is_global = false;
 			shortcut_is_disabled = false;
@@ -89,7 +99,10 @@ class PopupMenu : public Popup {
 	String _get_accel_text(int p_item) const;
 	int _get_mouse_over(const Point2 &p_over) const;
 	virtual Size2 get_minimum_size() const;
-	void _scroll(float p_factor, const Point2 &p_over);
+
+	int _get_items_total_height() const;
+	void _scroll_to_item(int p_item);
+
 	void _gui_input(const Ref<InputEvent> &p_event);
 	void _activate_submenu(int over, bool p_by_keyboard = false);
 	void _submenu_timeout();
@@ -113,6 +126,14 @@ class PopupMenu : public Popup {
 	uint64_t search_time_msec;
 	String search_string;
 
+	MarginContainer *margin_container;
+	ScrollContainer *scroll_container;
+	Control *control;
+	real_t max_height;
+
+	void _draw_items();
+	void _draw_background();
+
 protected:
 	virtual bool has_point(const Point2 &p_point) const;
 
@@ -215,6 +236,9 @@ public:
 	void set_allow_search(bool p_allow);
 	bool get_allow_search() const;
 
+	void set_max_height(real_t p_max_height);
+	real_t get_max_height() const;
+
 	virtual void popup(const Rect2 &p_bounds = Rect2());
 
 	void set_hide_on_window_lose_focus(bool p_enabled);