add new Box container for Canvas.

API subject to change and improvement

3 files changed, 416 insertions, 0 deletions

diff --git a/libs/canvas/box.cc b/libs/canvas/box.cc
new file mode 100644
index 0000000000..d7d0c90548
--- /dev/null
+++ b/libs/canvas/box.cc
@@ -0,0 +1,310 @@
+/*
+    Copyright (C) 2011-2014 Paul Davis
+    Author: Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <algorithm>
+
+#include "canvas/box.h"
+#include "canvas/rectangle.h"
+
+using namespace ArdourCanvas;
+
+Box::Box (Canvas* canvas, Orientation o)
+	: Item (canvas)
+	, orientation (o)
+	, spacing (0)
+	, top_padding (0), right_padding (0), bottom_padding (0), left_padding (0)
+	, top_margin (0), right_margin (0), bottom_margin (0), left_margin (0)
+	, homogenous (false)
+{
+	self = new Rectangle (this);
+	self->set_outline (false);
+	self->set_fill (false);
+}
+
+Box::Box (Item* parent, Orientation o)
+	: Item (parent)
+	, orientation (o)
+	, spacing (0)
+	, top_padding (0), right_padding (0), bottom_padding (0), left_padding (0)
+	, top_margin (0), right_margin (0), bottom_margin (0), left_margin (0)
+{
+	self = new Rectangle (this);
+	self->set_outline (false);
+	self->set_fill (false);
+}
+
+
+Box::Box (Item* parent, Duple const & p, Orientation o)
+	: Item (parent, p)
+	, orientation (o)
+	, spacing (0)
+	, top_padding (0), right_padding (0), bottom_padding (0), left_padding (0)
+	, top_margin (0), right_margin (0), bottom_margin (0), left_margin (0)
+{
+	self = new Rectangle (this);
+	self->set_outline (false);
+	self->set_fill (false);
+}
+
+void
+Box::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
+{
+	Item::render_children (area, context);
+}
+
+void
+Box::compute_bounding_box () const
+{
+	_bounding_box = boost::none;
+
+	if (_items.empty()) {
+		_bounding_box_dirty = false;
+		return;
+	}
+
+	add_child_bounding_boxes (!collapse_on_hide);
+
+	if (_bounding_box) {
+		Rect r = _bounding_box.get();
+
+		_bounding_box = r.expand (top_padding + outline_width() + top_margin,
+		                          right_padding + outline_width() + right_margin,
+		                          bottom_padding + outline_width() + bottom_margin,
+		                          left_padding + outline_width() + left_margin);
+	}
+
+	_bounding_box_dirty = false;
+}
+
+void
+Box::set_spacing (double s)
+{
+	spacing = s;
+}
+
+void
+Box::set_padding (double t, double r, double b, double l)
+{
+	double last = t;
+
+	top_padding = t;
+
+	if (r >= 0) {
+		last = r;
+	}
+	right_padding = last;
+	if (b >= 0) {
+		last = b;
+	}
+	bottom_padding = last;
+	if (l >= 0) {
+		last = l;
+	}
+	left_padding = last;
+}
+
+void
+Box::set_margin (double t, double r, double b, double l)
+{
+	double last = t;
+	top_margin = t;
+	if (r >= 0) {
+		last = r;
+	}
+	right_margin = last;
+	if (b >= 0) {
+		last = b;
+	}
+	bottom_margin = last;
+	if (l >= 0) {
+		last = l;
+	}
+	left_margin = last;
+}
+
+void
+Box::reset_self ()
+{
+	if (_bounding_box_dirty) {
+		compute_bounding_box ();
+	}
+
+	if (!_bounding_box) {
+		self->hide ();
+		return;
+	}
+
+	Rect r (_bounding_box.get());
+
+	/* XXX need to shrink by margin */
+
+	self->set (r);
+}
+
+void
+Box::reposition_children ()
+{
+	Duple previous_edge (0, 0);
+	Distance largest_width = 0;
+	Distance largest_height = 0;
+
+	if (homogenous) {
+
+		for (std::list<Item*>::iterator i = _items.begin(); ++i != _items.end(); ++i) {
+			boost::optional<Rect> bb = (*i)->bounding_box();
+			if (bb) {
+				largest_height = std::max (largest_height, bb.get().height());
+				largest_width = std::max (largest_height, bb.get().width());
+			}
+		}
+	}
+
+	for (std::list<Item*>::iterator i = _items.begin(); ++i != _items.end(); ++i) {
+
+		(*i)->set_position (previous_edge);
+
+		if (orientation == Vertical) {
+
+			Distance shift = 0;
+
+			if (homogenous) {
+				shift = largest_height;
+			} else {
+				boost::optional<Rect> bb = (*i)->bounding_box();
+
+				if (!(*i)->visible()) {
+					/* invisible child */
+					if (!collapse_on_hide) {
+						/* still add in its size */
+						if (bb) {
+							shift += bb.get().height();
+						}
+					}
+				} else {
+					if (bb) {
+						shift += bb.get().height();
+					}
+				}
+			}
+
+			previous_edge = previous_edge.translate (Duple (0, spacing + shift));
+		} else {
+
+			Distance shift = 0;
+
+			if (homogenous) {
+				shift = largest_width;
+			} else {
+				boost::optional<Rect> bb = (*i)->bounding_box();
+
+				if (!(*i)->visible()) {
+					if (!collapse_on_hide) {
+						if (bb) {
+							shift += bb.get().width();
+						}
+					}
+				} else {
+					if (bb) {
+						shift += bb.get().width();
+					}
+				}
+			}
+
+			previous_edge = previous_edge.translate (Duple (0, spacing + shift));
+		}
+	}
+
+	_bounding_box_dirty = true;
+	reset_self ();
+}
+
+void
+Box::pack_end (Item* i, double extra_padding)
+{
+	if (!i) {
+		return;
+	}
+
+	/* prepend new child */
+	Item::add_front (i);
+	reposition_children ();
+}
+void
+Box::pack_start (Item* i, double extra_padding)
+{
+	if (!i) {
+		return;
+	}
+
+	/* append new child */
+	Item::add (i);
+	reposition_children ();
+}
+
+void
+Box::add (Item* i)
+{
+	pack_start (i);
+}
+
+void
+Box::child_changed ()
+{
+	/* catch visibility and size changes */
+
+	Item::child_changed ();
+	reposition_children ();
+}
+
+void
+Box::set_collapse_on_hide (bool yn)
+{
+	if (collapse_on_hide != yn) {
+		collapse_on_hide = yn;
+		reposition_children ();
+	}
+}
+
+/*----*/
+
+VBox::VBox (Canvas* c)
+	: Box (c, Vertical)
+{
+}
+VBox::VBox (Item* i)
+	: Box (i, Vertical)
+{
+}
+VBox::VBox (Item* i, Duple const & position)
+	: Box (i, position, Vertical)
+{
+}
+
+HBox::HBox (Canvas* c)
+	: Box (c, Horizontal)
+{
+}
+HBox::HBox (Item* i)
+	: Box (i, Horizontal)
+{
+}
+HBox::HBox (Item* i, Duple const & position)
+	: Box (i, position, Horizontal)
+{
+}
diff --git a/libs/canvas/canvas/box.h b/libs/canvas/canvas/box.h
new file mode 100644
index 0000000000..b3b2b85303
--- /dev/null
+++ b/libs/canvas/canvas/box.h
@@ -0,0 +1,105 @@
+/*
+    Copyright (C) 2011-2014 Paul Davis
+    Original Author: Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef __CANVAS_BOX_H__
+#define __CANVAS_BOX_H__
+
+#include "canvas/item.h"
+
+namespace ArdourCanvas
+{
+
+class Rectangle;
+
+/** a Container is an item which has no content of its own
+ * but renders its children in some geometrical arrangement.
+ *
+ * Imagined examples of containers:
+ *
+ *   Container: renders each child at the child's self-determined position
+ *   Box: renders each child along an axis (vertical or horizontal)
+ *   Table/Grid: renders each child within a two-dimensional grid
+ *
+ *   Other?
+ */
+class LIBCANVAS_API Box : public Item
+{
+public:
+	enum Orientation {
+		Vertical,
+		Horizontal
+	};
+
+	Box (Canvas *, Orientation);
+	Box (Item *, Orientation);
+	Box (Item *, Duple const & position, Orientation);
+
+	void set_spacing (double s);
+	void set_padding (double top, double right = -1.0, double bottom = -1.0, double left = -1.0);
+	void set_margin (double top, double right = -1.0, double bottom = -1.0, double left = -1.0);
+
+	/* aliases so that CSS box model terms work */
+	void set_border_width (double w) { set_outline_width (w); }
+	void set_border_color (Color c)  { set_outline_color (c); }
+
+	void add (Item*);
+	void pack_start (Item*, double extra_padding = 0);
+	void pack_end (Item*, double extra_padding = 0);
+
+	void set_collapse_on_hide (bool);
+	void set_homogenous (bool);
+
+	void compute_bounding_box () const;
+	void render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const;
+
+  protected:
+	Orientation orientation;
+	double spacing;
+	double top_padding, right_padding, bottom_padding, left_padding;
+	double top_margin, right_margin, bottom_margin, left_margin;
+
+	void child_changed ();
+  private:
+	Rectangle *self;
+	bool collapse_on_hide;
+	bool homogenous;
+
+	void reset_self ();
+	void reposition_children ();
+};
+
+class LIBCANVAS_API VBox : public Box
+{
+  public:
+	VBox (Canvas *);
+	VBox (Item *);
+	VBox (Item *, Duple const & position);
+};
+
+class LIBCANVAS_API HBox : public Box
+{
+  public:
+	HBox (Canvas *);
+	HBox (Item *);
+	HBox (Item *, Duple const & position);
+};
+
+}
+
+#endif
diff --git a/libs/canvas/wscript b/libs/canvas/wscript
index b40f72412d..0038b783c6 100644
--- a/libs/canvas/wscript
+++ b/libs/canvas/wscript
@@ -30,6 +30,7 @@ path_prefix = 'libs/canvas/'
 canvas_sources = [
         'arc.cc',
         'arrow.cc',
+        'box.cc',
         'canvas.cc',
         'circle.cc',
         'colors.cc',