From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 7 Nov 2013 12:57:14 +0000 (+0200)
Subject: Support floating widgets in layouts
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=deebbb5d23f7bdad0e25fe7eeb0a3e5a4eaf761f;p=libs%2Fgltk.git

Support floating widgets in layouts

An arrangement class that automatically makes widgets floating is also
added.
---

diff --git a/source/floatingarrangement.cpp b/source/floatingarrangement.cpp
new file mode 100644
index 0000000..6e707e8
--- /dev/null
+++ b/source/floatingarrangement.cpp
@@ -0,0 +1,16 @@
+#include "floatingarrangement.h"
+
+namespace Msp {
+namespace GLtk {
+
+FloatingArrangement::FloatingArrangement(Layout &l):
+	Arrangement(l)
+{ }
+
+void FloatingArrangement::finish_widget(Widget &wdg)
+{
+	layout.set_floating(wdg, true);
+}
+
+} // namespace GLtk
+} // namespace Msp
diff --git a/source/floatingarrangement.h b/source/floatingarrangement.h
new file mode 100644
index 0000000..a4ebdd7
--- /dev/null
+++ b/source/floatingarrangement.h
@@ -0,0 +1,23 @@
+#ifndef FLOATINGARRANGEMENT_H_
+#define FLOATINGARRANGEMENT_H_
+
+#include "arrangement.h"
+
+namespace Msp {
+namespace GLtk {
+
+class FloatingArrangement: public Arrangement
+{
+public:
+	FloatingArrangement(Layout &);
+
+private:
+	virtual void process_widget(Widget &, Side, bool) { }
+	virtual void finish_widget(Widget &);
+	virtual void finish_slot() { }
+};
+
+} // namespace GLtk
+} // namespace Msp
+
+#endif
diff --git a/source/layout.cpp b/source/layout.cpp
index 5df7bc1..02e1ec4 100644
--- a/source/layout.cpp
+++ b/source/layout.cpp
@@ -211,22 +211,31 @@ void Layout::remove_widget(Widget &wdg)
 void Layout::update_slot_indices()
 {
 	n_active_slots = 0;
+	unsigned n_floating = 0;
 	for(list<Slot *>::iterator i=slots.begin(); i!=slots.end(); ++i)
 	{
 		if((*i)->widget.is_visible() || (*i)->ghost)
+		{
 			(*i)->index = n_active_slots++;
+			if((*i)->floating)
+				++n_floating;
+		}
 		else
 			(*i)->index = -1;
 	}
 
-	n_slack_vars[0] = 0;
-	n_slack_vars[1] = 0;
+	n_slack_vars[0] = n_floating*2;
+	n_slack_vars[1] = n_floating*2;
 	for(list<Slot *>::iterator i=slots.begin(); i!=slots.end(); ++i)
 		if((*i)->index>=0)
 		{
-			for(unsigned j=0; j<2; ++j)
-				if(((*i)->*(pointers[j].packing)).gravity==0)
-					n_slack_vars[j] += 2;
+			if(!(*i)->floating)
+			{
+				for(unsigned j=0; j<2; ++j)
+					if(((*i)->*(pointers[j].packing)).gravity==0)
+						n_slack_vars[j] += 2;
+			}
+
 			for(list<Constraint>::iterator j=(*i)->constraints.begin(); j!=(*i)->constraints.end(); ++j)
 				if(j->target.index>(*i)->index && (j->type&SLACK))
 					++n_slack_vars[j->type&1];
@@ -312,6 +321,16 @@ void Layout::set_ghost(Widget &wdg, bool g)
 	}
 }
 
+void Layout::set_floating(Widget &wdg, bool f)
+{
+	Slot &slot = get_slot_for_widget(wdg);
+
+	slot.floating = f;
+
+	update_slot_indices();
+	update();
+}
+
 void Layout::update()
 {
 	solve_constraints(HORIZONTAL, UPDATE);
@@ -358,7 +377,8 @@ void Layout::solve_constraints(int dir, SolveMode mode)
 		}
 		else
 		{
-			objective[(*i)->index*5] = ((*i)->*(ptrs.packing)).gravity/weight;
+			if(!(*i)->floating)
+				objective[(*i)->index*5] = ((*i)->*(ptrs.packing)).gravity/weight;
 			objective[(*i)->index*5+1] = (((*i)->*(ptrs.packing)).expand ? weight : -1);
 		}
 
@@ -380,18 +400,24 @@ void Layout::solve_constraints(int dir, SolveMode mode)
 			row.back() = geom.*(ptrs.dim)-margin.*(ptrs.high_margin);
 		}
 
-		if(((*i)->*(ptrs.packing)).gravity==0)
+		if((*i)->floating || ((*i)->*(ptrs.packing)).gravity==0)
 		{
-			/* Try to keep the widget as close to the center of the container
-			as possible.  Since linear programs can't express absolute values
-			directly, use two opposing slack variables that are optimized for
-			a low value. */
+			/* Try to keep the widget as close to a target position as possible.
+			Since linear programs can't express absolute values directly, use two
+			opposing slack variables that are optimized for a low value. */
+			float a = ((*i)->*(ptrs.packing)).gravity*0.5+0.5;
 			LinearProgram::Row row = linprog.add_row();
 			row[(*i)->index*5] = 1;
-			row[(*i)->index*5+1] = 0.5;
+			row[(*i)->index*5+1] = a;
 			row[k] = 1;
 			row[k+1] = -1;
-			row.back() = geom.*(ptrs.dim)/2;
+			if((*i)->floating)
+			{
+				const Geometry &cgeom = (*i)->widget.get_geometry();
+				row.back() = cgeom.*(ptrs.pos)+cgeom.*(ptrs.dim)*a;
+			}
+			else
+				row.back() = geom.*(ptrs.dim)/2;
 			objective[k] = -1;
 			objective[k+1] = -1;
 			k += 2;
@@ -470,7 +496,8 @@ Layout::Slot::Slot(Layout &l, Widget &w):
 	layout(l),
 	index(0),
 	widget(w),
-	ghost(false)
+	ghost(false),
+	floating(false)
 {
 	vert_pack.gravity = 1;
 	widget.signal_autosize_changed.connect(sigc::mem_fun(this, &Slot::autosize_changed));
diff --git a/source/layout.h b/source/layout.h
index 043d92c..141a15c 100644
--- a/source/layout.h
+++ b/source/layout.h
@@ -153,6 +153,7 @@ private:
 		Packing horiz_pack;
 		Packing vert_pack;
 		bool ghost;
+		bool floating;
 
 		Slot(Layout &, Widget &);
 
@@ -229,6 +230,8 @@ public:
 	/// Sets a widget as a ghost, taking up space even if it is hidden.
 	void set_ghost(Widget &, bool);
 
+	void set_floating(Widget &, bool);
+
 	void update();
 	void autosize(Geometry &);