Fix exception description

[libs/gltk.git] / source / layout.cpp

diff --git a/source/layout.cpp b/source/layout.cpp
index 7902902abf2541082b0d455de9a185145545a84c..b4cd7683c6bc60d2b615c7c46323b773e4a668cf 100644 (file)
--- 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()
@@ -211,22 +211,34 @@ 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_constraints[0] = 0;
-       n_slack_constraints[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)
                {
+                       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_constraints[j->type&1];
+                                       ++n_slack_vars[j->type&1];
                }
 }
 
@@ -247,7 +259,7 @@ Layout::ConstraintType Layout::complement(ConstraintType type)
 void Layout::create_constraint(Widget &src, ConstraintType type, Widget &tgt, int sp)
 {
        if(&src==&tgt)
-               throw invalid_argument("&src==&tgt");
+               throw invalid_argument("Layout::create_constraint");
 
        Slot &src_slot = get_slot_for_widget(src);
        Slot &tgt_slot = get_slot_for_widget(tgt);
@@ -282,6 +294,7 @@ void Layout::set_gravity(Widget &wdg, int h, int v)
        slot.horiz_pack.gravity = h;
        slot.vert_pack.gravity = v;
 
+       update_slot_indices();
        update();
 }
 
@@ -308,6 +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);
@@ -338,8 +361,9 @@ 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)
@@ -353,7 +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);
                }
 
@@ -375,14 +400,27 @@ 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)
                {
-                       /* 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 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+2] = 1;
-                       row[(*i)->index*5+3] = -1;
+                       row[(*i)->index*5] = 1;
+                       row[(*i)->index*5+1] = a;
+                       row[k] = 1;
+                       row[k+1] = -1;
+                       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;
                }
 
                {
@@ -396,7 +434,6 @@ 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)
                        {
@@ -459,27 +496,24 @@ 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));
        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();