From 2f1c7d6861c801e24a003ee5f6132032e04c9bbe Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 11 Dec 2007 08:00:41 +0000
Subject: [PATCH] Make widgets aware of their parents Support removing widgets
 from panels

---
 source/panel.cpp  | 15 +++++++++++++--
 source/panel.h    |  1 +
 source/widget.cpp | 22 +++++++++++++++++++++-
 source/widget.h   | 19 ++++++++++++++++++-
 4 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/source/panel.cpp b/source/panel.cpp
index 529ec19..36585c9 100644
--- a/source/panel.cpp
+++ b/source/panel.cpp
@@ -27,15 +27,26 @@ Panel::Panel(const Resources &r):
 
 Panel::~Panel()
 {
-	for(ChildSeq::iterator i=children.begin(); i!=children.end(); ++i)
-		delete *i;
+	while(!children.empty())
+		delete children.front();
 }
 
 void Panel::add(Widget &wdg)
 {
+	set_parent(wdg, this);
 	children.push_back(&wdg);
 }
 
+void Panel::remove(Widget &wdg)
+{
+	ChildSeq::iterator i=find(children.begin(), children.end(), &wdg);
+	if(i!=children.end())
+	{
+		set_parent(wdg, 0);
+		children.erase(i);
+	}
+}
+
 void Panel::button_press(int x, int y, unsigned btn)
 {
 	if(pointer_grab>0)
diff --git a/source/panel.h b/source/panel.h
index 7279d78..3d26875 100644
--- a/source/panel.h
+++ b/source/panel.h
@@ -50,6 +50,7 @@ public:
 	~Panel();
 
 	void add(Widget &);
+	void remove(Widget &);
 
 	virtual void button_press(int, int, unsigned);
 	virtual void button_release(int, int, unsigned);
diff --git a/source/widget.cpp b/source/widget.cpp
index e20ea82..e41310a 100644
--- a/source/widget.cpp
+++ b/source/widget.cpp
@@ -7,6 +7,7 @@ Distributed under the LGPL
 
 #include <msp/gl/matrix.h>
 #include <msp/gl/transform.h>
+#include "panel.h"
 #include "resources.h"
 #include "widget.h"
 
@@ -19,9 +20,16 @@ Widget::Widget(const Resources &r):
 	res(r),
 	style(0),
 	state(NORMAL),
-	visible(true)
+	visible(true),
+	parent(0)
 { }
 
+Widget::~Widget()
+{
+	if(parent)
+		parent->remove(*this);
+}
+
 void Widget::set_position(int x, int y)
 {
 	geom.x=x;
@@ -100,6 +108,18 @@ void Widget::update_style()
 	style=res.get<Style>(sname);
 }
 
+void Widget::set_parent(Panel *p)
+{
+	if(parent && p)
+		throw InvalidState("Widget is already in a Panel");
+	parent=p;
+}
+
+void Widget::set_parent(Widget &w, Panel *p)
+{
+	w.set_parent(p);
+}
+
 
 Widget::Loader::Loader(Widget &w):
 	wdg(w)
diff --git a/source/widget.h b/source/widget.h
index 255f042..6cb5e4a 100644
--- a/source/widget.h
+++ b/source/widget.h
@@ -15,6 +15,7 @@ Distributed under the LGPL
 namespace Msp {
 namespace GLtk {
 
+class Panel;
 class Part;
 class Resources;
 class Style;
@@ -47,10 +48,11 @@ protected:
 	const Style *style;
 	State state;
 	bool visible;
+	Panel *parent;
 
 	Widget(const Resources &);
 public:
-	virtual ~Widget() { }
+	virtual ~Widget();
 	void set_position(int, int);
 	void set_size(unsigned, unsigned);
 	void set_geometry(const Geometry &);
@@ -88,7 +90,22 @@ protected:
 	*/
 	virtual const char *get_class() const { return "widget"; }
 
+	/**
+	Gets a style object from the resource collection based on the class and
+	style names of the widget.
+	*/
 	void update_style();
+
+	/**
+	Sets the widget's parent Panel.  The widget must be unparented when calling
+	this function.
+	*/
+	void set_parent(Panel *);
+
+	/**
+	A helper function to set the parent of another widget.
+	*/
+	void set_parent(Widget &, Panel *);
 };
 
 } // namespace GLtk
-- 
2.43.0