initial skeleton for a Grid canvas item

2 files changed, 276 insertions, 0 deletions

diff --git a/libs/canvas/canvas/grid.h b/libs/canvas/canvas/grid.h
new file mode 100644
index 0000000000..a13cdf0a22
--- /dev/null
+++ b/libs/canvas/canvas/grid.h
@@ -0,0 +1,71 @@
+/*
+    Copyright (C) 2018 Paul Davis
+
+    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_GRID_H__
+#define __CANVAS_GRID_H__
+
+#include "canvas/item.h"
+
+namespace ArdourCanvas
+{
+
+class Rectangle;
+
+/** Canvas container that renders its children in a grid layout
+ */
+class LIBCANVAS_API Grid : public Item
+{
+public:
+	Grid (Canvas *);
+	Grid (Item *);
+	Grid (Item *, Duple const & position);
+
+	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 place(Item*, Duple coord);
+
+	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:
+	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 ();
+};
+
+}
+
+#endif
diff --git a/libs/canvas/grid.cc b/libs/canvas/grid.cc
new file mode 100644
index 0000000000..cc12feb8db
--- /dev/null
+++ b/libs/canvas/grid.cc
@@ -0,0 +1,205 @@
+/*
+    Copyright (C) 2018 Paul Davis
+
+    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/grid.h"
+#include "canvas/rectangle.h"
+
+using namespace ArdourCanvas;
+
+Grid::Grid (Canvas* canvas)
+	: Item (canvas)
+	, 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);
+}
+
+Grid::Grid (Item* parent)
+	: Item (parent)
+	, 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);
+}
+
+Grid::Grid (Item* parent, Duple const & p)
+	: Item (parent, p)
+	, 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);
+}
+
+void
+Grid::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
+{
+	Item::render_children (area, context);
+}
+
+void
+Grid::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
+Grid::set_spacing (double s)
+{
+	spacing = s;
+}
+
+void
+Grid::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
+Grid::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
+Grid::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
+Grid::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_width, bb.get().width());
+			}
+		}
+	}
+
+	for (std::list<Item*>::iterator i = _items.begin(); ++i != _items.end(); ++i) {
+
+	}
+
+	_bounding_box_dirty = true;
+	reset_self ();
+}
+
+void
+Grid::place (Item* i, Duple at)
+{
+
+}
+
+void
+Grid::child_changed ()
+{
+	/* catch visibility and size changes */
+
+	Item::child_changed ();
+	reposition_children ();
+}
+
+void
+Grid::set_collapse_on_hide (bool yn)
+{
+	if (collapse_on_hide != yn) {
+		collapse_on_hide = yn;
+		reposition_children ();
+	}
+}