From 8497298d730b9a24ad783f76bef76ca7c58b78e3 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 26 Jan 2021 22:39:04 +0100
Subject: [PATCH] Custom themable frame container

As opposed to Gtk::Frame, this allows the background color of
the content, inside the frame to be set and follows Ardour theme
options.
---
 libs/widgets/frame.cc        | 358 +++++++++++++++++++++++++++++++++++
 libs/widgets/widgets/frame.h |  81 ++++++++
 libs/widgets/wscript         |   1 +
 3 files changed, 440 insertions(+)
 create mode 100644 libs/widgets/frame.cc
 create mode 100644 libs/widgets/widgets/frame.h

diff --git a/libs/widgets/frame.cc b/libs/widgets/frame.cc
new file mode 100644
index 0000000000..6b815510fc
--- /dev/null
+++ b/libs/widgets/frame.cc
@@ -0,0 +1,358 @@
+/*
+ * Copyright (C) 2020 Robin Gareus <robin@gareus.org>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <cassert>
+
+#include "gtkmm2ext/colors.h"
+#include "gtkmm2ext/utils.h"
+
+#include "widgets/frame.h"
+#include "widgets/ui_config.h"
+
+using namespace std;
+using namespace Gtk;
+using namespace ArdourWidgets;
+
+Frame::Frame (Orientation orientation, bool boxy)
+	: _orientation (orientation)
+	, _w (0)
+	, _current_parent (0)
+	, _border (0)
+	, _padding (4)
+	, _label_pad_w (5)
+	, _label_pad_h (2)
+	, _label_left (12)
+	, _text_width (0)
+	, _text_height (0)
+	, _alloc_x0 (0)
+	, _alloc_y0 (0)
+	, _boxy (boxy)
+{
+	set_name ("Frame");
+	ensure_style ();
+	_min_size.width = _min_size.height = 0;
+	_layout = Pango::Layout::create (get_pango_context ());
+
+	/* provide bg color for cairo child widgets */
+	g_object_set_data (G_OBJECT (gobj ()), "has_cairo_widget_background_info", (void*)0xfeedface);
+	UIConfigurationBase::instance().DPIReset.connect (sigc::mem_fun (*this, &Frame::on_name_changed));
+}
+
+Frame::~Frame ()
+{
+	if (_parent_style_change) {
+		_parent_style_change.disconnect ();
+	}
+	if (_w) {
+		_w->unparent ();
+	}
+}
+
+void
+Frame::on_add (Widget* w)
+{
+	if (_w || !w) {
+		return;
+	}
+
+	Bin::on_add (w);
+	_w = w;
+	queue_resize ();
+}
+
+void
+Frame::on_remove (Gtk::Widget* w)
+{
+	Bin::on_remove (w);
+	assert (_w == w);
+	_w = 0;
+}
+
+void
+Frame::on_size_request (GtkRequisition* r)
+{
+	Bin::on_size_request (r);
+	_border = get_border_width ();
+
+	_layout->set_markup (_label_text);
+	if (!_layout->get_text ().empty ()) {
+		_layout->get_pixel_size (_text_width, _text_height);
+	} else {
+		_text_width = _text_height = 0;
+	}
+
+	if (_w) {
+		_w->size_request (*r);
+	} else {
+		r->width  = 0;
+		r->height = 0;
+	}
+
+	if (_text_width > 0) {
+		if (_orientation == Horizontal) {
+			r->width  = max (r->width, _text_width + _label_pad_w * 2 + _label_left);
+			r->width  += 2 * (_padding + _border);
+			r->height += 2 * (_padding + _border + _label_pad_h) + _text_height;
+		} else {
+			r->height = max (r->height, _text_width + _label_pad_w * 2 + _label_left);
+			r->width  += 2 * (_padding + _border + _label_pad_h) + _text_height;
+			r->height += 2 * (_padding + _border);
+		}
+	} else {
+		r->height += 2 * (_padding + _border);
+		r->width += 2 * (_padding + _border);
+	}
+	_min_size = *r;
+}
+
+void
+Frame::on_size_allocate (Allocation& alloc)
+{
+	Bin::on_size_allocate (alloc);
+	_alloc_x0 = alloc.get_x ();
+	_alloc_y0 = alloc.get_y ();
+
+	Allocation child_alloc;
+	if (alloc.get_width () < _min_size.width || alloc.get_height () < _min_size.height) {
+#if 0
+		printf ("Frame::on_size_allocate %dx%d < %dx%d\n", alloc.get_width (), alloc.get_height (), _min_size.width, _min_size.height);
+#endif
+		return;
+	}
+
+	int pb_l, pb_t;
+	if (_orientation == Horizontal) {
+		pb_l = _padding + _border;
+		pb_t = _padding + _border + (_text_width > 0 ? _label_pad_h : 0);
+
+		child_alloc.set_x (alloc.get_x () + pb_l);
+		child_alloc.set_y (alloc.get_y () + pb_t + _text_height);
+		child_alloc.set_width (alloc.get_width () - pb_l * 2);
+		child_alloc.set_height (alloc.get_height () - pb_t * 2 - _text_height);
+	} else {
+		pb_l = _padding + _border + (_text_width > 0 ? _label_pad_h : 0);;
+		pb_t = _padding + _border;
+
+		child_alloc.set_x (alloc.get_x () + pb_l + _text_height);
+		child_alloc.set_y (alloc.get_y () + pb_t);
+		child_alloc.set_width (alloc.get_width () - pb_l * 2 - _text_height);
+		child_alloc.set_height (alloc.get_height () - pb_t * 2);
+	}
+
+	if (_w) {
+		_w->size_allocate (child_alloc);
+	}
+}
+
+void
+Frame::on_style_changed (const Glib::RefPtr<Gtk::Style>& style)
+{
+	Bin::on_style_changed (style);
+	Glib::RefPtr<Gtk::Style> const& new_style = get_style ();
+	if (_layout && (_layout->get_font_description ().gobj () == 0 || _layout->get_font_description () != new_style->get_font ())) {
+		_layout->set_font_description (new_style->get_font ());
+		queue_resize ();
+	} else if (is_realized ()) {
+		queue_resize ();
+	}
+}
+
+void
+Frame::on_name_changed ()
+{
+	ensure_style ();
+	queue_resize ();
+	queue_draw ();
+}
+
+Glib::RefPtr<Style>
+Frame::get_parent_style ()
+{
+	Widget* parent = get_parent ();
+
+	while (parent) {
+		if (parent->get_has_window ()) {
+			break;
+		}
+		parent = parent->get_parent ();
+	}
+
+	if (parent && parent->get_has_window ()) {
+		if (_current_parent != parent) {
+			if (_parent_style_change) {
+				_parent_style_change.disconnect ();
+			}
+			_current_parent      = parent;
+			_parent_style_change = parent->signal_style_changed ().connect (mem_fun (*this, &Frame::on_style_changed));
+		}
+		return parent->get_style ();
+	}
+
+	return get_style ();
+}
+
+bool
+Frame::on_expose_event (GdkEventExpose* ev)
+{
+	Glib::RefPtr<Style> pstyle (get_parent_style ());
+	Glib::RefPtr<Style> style (get_style ());
+
+	const bool  boxy = _boxy | boxy_buttons ();
+	const float crad = boxy ? 0 : std::max (2.f, 3.f * UIConfigurationBase::instance ().get_ui_scale ());
+	const int   lbl  = ceil (_text_height / 2.0);
+	Gdk::Color  pbg  = pstyle->get_bg (get_state ());
+	Gdk::Color  edge = pstyle->get_dark (get_state ());
+	Gdk::Color  bg   = style->get_bg (get_state ());
+	Gdk::Color  text = style->get_text (get_state ());
+
+	if (_edge_color) {
+		edge = _edge_color.value ();
+	}
+
+	Cairo::RefPtr<Cairo::Context> cr = get_window ()->create_cairo_context ();
+	cr->rectangle (ev->area.x, ev->area.y, ev->area.width, ev->area.height);
+	cr->clip_preserve ();
+	cr->set_source_rgb (pbg.get_red_p (), pbg.get_green_p (), pbg.get_blue_p ());
+	cr->fill ();
+
+	cr->translate (_alloc_x0, _alloc_y0);
+
+	int ll, tp, tw2, th2;
+	if (_orientation == Horizontal) {
+		ll  = _border;
+		tp  = _border + (_text_width > 0 ? _label_pad_h : 0);
+		th2 = lbl;
+		tw2 = 0;
+	} else {
+		ll = _border + (_text_width > 0 ? _label_pad_h : 0);
+		tp = _border;
+		th2 = 0;
+		tw2 = lbl;
+	}
+
+	/* Edge */
+	assert (_padding >= 2);
+	Gtkmm2ext::rounded_rectangle (cr, ll + tw2, tp + th2, get_width () - ll * 2 - tw2, get_height () - tp * 2 - th2, crad + 1.5);
+	cr->set_source_rgb (edge.get_red_p (), edge.get_green_p (), edge.get_blue_p ());
+	cr->fill ();
+	Gtkmm2ext::rounded_rectangle (cr, ll + tw2 + 1, tp + th2 + 1, get_width () - ll * 2 - tw2 - 2, get_height () - tp * 2 - th2 - 2, crad);
+	cr->set_source_rgb (bg.get_red_p (), bg.get_green_p (), bg.get_blue_p ());
+	cr->fill ();
+
+	if (_text_width > 0) {
+		int lft, top;
+		static const double degrees = M_PI / 180.0;
+		double r = crad + 1.5;
+
+		cr->set_source_rgb (bg.get_red_p (), bg.get_green_p (), bg.get_blue_p ());
+
+		if (_orientation == Horizontal) {
+			lft = ll + _padding + _label_left;
+			top = _border;
+			Gtkmm2ext::rounded_top_rectangle (cr, lft, top, _text_width + 2 * _label_pad_w, _text_height + 2 * _label_pad_h, crad + 1.5);
+			cr->fill ();
+
+			double x = lft + .5;
+			double y = top + .5;
+			double w = _text_width + 2 * _label_pad_w;
+			double h = _label_pad_h + th2;
+
+			cr->move_to (x, y + h);
+			cr->arc (x + r, y + r, r, 180 * degrees, 270 * degrees);   //tl
+			cr->arc (x + w - r, y + r, r, -90 * degrees, 0 * degrees); //tr
+			cr->line_to (x + w, y + h);
+		} else {
+			lft = _border;
+			top = get_height () - ll - _padding - _label_left - _text_width;
+			Gtkmm2ext::rounded_left_half_rectangle (cr, lft, top, _text_height + 2 * _label_pad_h, _text_width + 2 * _label_pad_w, crad + 1.5);
+			cr->fill ();
+			double x = lft + .5;
+			double y = top + .5;
+			double w = _label_pad_h + tw2;
+			double h = _text_width + 2 * _label_pad_w;
+
+			cr->move_to (x+w, y + h);
+			cr->arc (x + r, y + h - r, r, 90 * degrees, 180 * degrees);  //bl
+			cr->arc (x + r, y + r, r, 180 * degrees, 270 * degrees);  //tl
+			cr->line_to (x + w, y);
+		}
+
+		cr->set_line_width (1);
+		cr->set_source_rgb (edge.get_red_p (), edge.get_green_p (), edge.get_blue_p ());
+		cr->stroke ();
+
+		cr->save ();
+		cr->set_source_rgb (text.get_red_p (), text.get_green_p (), text.get_blue_p ());
+		if (_orientation == Horizontal) {
+			cr->move_to (lft + _label_pad_w, top + _padding + _label_pad_h - th2 / 2 - 1);
+		} else {
+			cr->move_to (lft + _padding + _label_pad_h - tw2 / 2 - 1, top + _label_pad_w + _text_width);
+			cr->rotate (M_PI / -2.0);
+		}
+		_layout->update_from_cairo_context (cr);
+		_layout->show_in_cairo_context (cr);
+		cr->restore ();
+	}
+
+	if (_w->is_visible ()) {
+		propagate_expose (*_w, ev);
+	}
+	return true;
+}
+
+void
+Frame::set_padding (int p)
+{
+	if (_padding == p + 2 || p < 0) {
+		return;
+	}
+	_padding = p + 2;
+	queue_resize ();
+}
+
+void
+Frame::reset_edge_color ()
+{
+	_edge_color.reset ();
+}
+
+void
+Frame::set_edge_color (Gtkmm2ext::Color c)
+{
+	double r, g, b, a;
+	Gdk::Color color;
+
+	Gtkmm2ext::color_to_rgba (c, r, g, b, a);
+	color.set_rgb_p (r, g, b);
+
+	if (_edge_color == color) {
+		return;
+	}
+	_edge_color = color;
+	queue_draw ();
+}
+
+void
+Frame::set_label (std::string const& t)
+{
+	if (_label_text == t) {
+		return;
+	}
+	_label_text = t;
+	queue_resize ();
+}
diff --git a/libs/widgets/widgets/frame.h b/libs/widgets/widgets/frame.h
new file mode 100644
index 0000000000..875670eaae
--- /dev/null
+++ b/libs/widgets/widgets/frame.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2020 Robin Gareus <robin@gareus.org>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _WIDGETS_FRAME_H_
+#define _WIDGETS_FRAME_H_
+
+#include <boost/optional.hpp>
+#include <gtkmm/bin.h>
+
+#include "gtkmm2ext/cairo_theme.h"
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API Frame : public Gtk::Bin, public Gtkmm2ext::CairoTheme
+{
+public:
+	enum Orientation {
+		Horizontal,
+		Vertical
+	};
+
+	Frame (Orientation orientation = Horizontal, bool force_boxy = false);
+	~Frame ();
+
+	void set_label (std::string const&);
+	void set_padding (int);
+	void set_edge_color (Gtkmm2ext::Color);
+	void reset_edge_color ();
+
+protected:
+	void on_add (Gtk::Widget*);
+	void on_remove (Gtk::Widget*);
+	void on_size_request (GtkRequisition*);
+	void on_size_allocate (Gtk::Allocation&);
+	bool on_expose_event (GdkEventExpose*);
+	void on_style_changed (const Glib::RefPtr<Gtk::Style>&);
+	void on_name_changed ();
+
+private:
+	Glib::RefPtr<Gtk::Style> get_parent_style ();
+
+	Orientation                 _orientation;
+	Gtk::Widget*                _w;
+	Gtk::Widget*                _current_parent;
+	sigc::connection            _parent_style_change;
+	Glib::RefPtr<Pango::Layout> _layout;
+	std::string                 _label_text;
+	boost::optional<Gdk::Color> _edge_color;
+	GtkRequisition              _min_size;
+
+	int  _border;
+	int  _padding;
+	int  _label_pad_w;
+	int  _label_pad_h;
+	int  _label_left;
+	int  _text_width;
+	int  _text_height;
+	int  _alloc_x0;
+	int  _alloc_y0;
+	bool _boxy;
+};
+
+} // namespace ArdourWidgets
+
+#endif
diff --git a/libs/widgets/wscript b/libs/widgets/wscript
index 8c052f5bed..1a1b24f5db 100644
--- a/libs/widgets/wscript
+++ b/libs/widgets/wscript
@@ -39,6 +39,7 @@ widgets_sources = [
         'eventboxext.cc',
         'choice.cc',
         'fastmeter.cc',
+        'frame.cc',
         'focus_entry.cc',
         'pane.cc',
         'paths_dialog.cc',