X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flayout.cpp;h=5df7bc1f77d2a16f87a02f80e4eea6892a2d3564;hb=729cb06f85e2888a7ac1e72375380257936106c9;hp=7902902abf2541082b0d455de9a185145545a84c;hpb=d2d5b4c4dedf90a42dd2baff8334318b1d000f64;p=libs%2Fgltk.git

diff --git a/source/layout.cpp b/source/layout.cpp
index 7902902..5df7bc1 100644
--- a/source/layout.cpp
+++ b/source/layout.cpp
@@ -92,8 +92,8 @@ Layout::Layout():
 	row_spacing(5),
 	col_spacing(4)
 {
-	n_slack_constraints[0] = 0;
-	n_slack_constraints[1] = 0;
+	n_slack_vars[0] = 0;
+	n_slack_vars[1] = 0;
 }
 
 Layout::~Layout()
@@ -219,14 +219,17 @@ void Layout::update_slot_indices()
 			(*i)->index = -1;
 	}
 
-	n_slack_constraints[0] = 0;
-	n_slack_constraints[1] = 0;
+	n_slack_vars[0] = 0;
+	n_slack_vars[1] = 0;
 	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;
 			for(list<Constraint>::iterator j=(*i)->constraints.begin(); j!=(*i)->constraints.end(); ++j)
 				if(j->target.index>(*i)->index && (j->type&SLACK))
-					++n_slack_constraints[j->type&1];
+					++n_slack_vars[j->type&1];
 		}
 }
 
@@ -282,6 +285,7 @@ void Layout::set_gravity(Widget &wdg, int h, int v)
 	slot.horiz_pack.gravity = h;
 	slot.vert_pack.gravity = v;
 
+	update_slot_indices();
 	update();
 }
 
@@ -338,8 +342,9 @@ void Layout::solve_constraints(int dir, SolveMode mode)
 	five columns for each widget, and one constant column.  The first and second
 	columns of a widget are its position and dimension, respectively.  The
 	remaining three are slack columns; see below for their purposes. */
-	LinearProgram linprog(n_active_slots*5+n_slack_constraints[dir]+1);
+	LinearProgram linprog(n_active_slots*5+n_slack_vars[dir]+1);
 	float weight = slots.size();
+	unsigned k = n_active_slots*5;
 	for(list<Slot *>::iterator i=slots.begin(); i!=slots.end(); ++i)
 	{
 		if((*i)->index<0)
@@ -377,12 +382,19 @@ void Layout::solve_constraints(int dir, SolveMode mode)
 
 		if(((*i)->*(ptrs.packing)).gravity==0)
 		{
-			/* This forces the widget's distance from the left and right edge of
-			the container to be equal.  It's a bit of a hack, but more time and
-			thought is needed for a better solution. */
+			/* 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. */
 			LinearProgram::Row row = linprog.add_row();
-			row[(*i)->index*5+2] = 1;
-			row[(*i)->index*5+3] = -1;
+			row[(*i)->index*5] = 1;
+			row[(*i)->index*5+1] = 0.5;
+			row[k] = 1;
+			row[k+1] = -1;
+			row.back() = geom.*(ptrs.dim)/2;
+			objective[k] = -1;
+			objective[k+1] = -1;
+			k += 2;
 		}
 
 		{
@@ -396,7 +408,6 @@ void Layout::solve_constraints(int dir, SolveMode mode)
 
 		/* Add rows for user-defined constraints.  Constraints are always added
 		in pairs, so it's only necessary to create a row for one half. */
-		unsigned k = n_active_slots*5;
 		for(list<Constraint>::iterator j=(*i)->constraints.begin(); j!=(*i)->constraints.end(); ++j)
 			if(j->target.index>(*i)->index && (j->type&1)==dir)
 			{
@@ -464,22 +475,18 @@ Layout::Slot::Slot(Layout &l, Widget &w):
 	vert_pack.gravity = 1;
 	widget.signal_autosize_changed.connect(sigc::mem_fun(this, &Slot::autosize_changed));
 	widget.signal_visibility_changed.connect(sigc::mem_fun(this, &Slot::visibility_changed));
-	widget.autosize();
-	autosize_geom = widget.get_geometry();
+	widget.autosize(autosize_geom);
 }
 
 void Layout::Slot::autosize_changed()
 {
-	widget.autosize();
-	autosize_geom = widget.get_geometry();
+	widget.autosize(autosize_geom);
 
 	if(!widget.is_visible() && !ghost)
 		return;
 
-	// If the widget fits in the area it had, just leave it there.
-	if(autosize_geom.w<=geom.w && autosize_geom.h<=geom.h)
-		widget.set_geometry(geom);
-	else
+	// Only trigger an update if the widget won't fit in its current area.
+	if(autosize_geom.w>geom.w || autosize_geom.h>geom.h)
 	{
 		layout.container->signal_autosize_changed.emit();
 		layout.update();