refine stereo-panner GUI:

* cairo pixel alignment
* use pango for text

1 files changed, 60 insertions, 46 deletions

diff --git a/gtk2_ardour/stereo_panner.cc b/gtk2_ardour/stereo_panner.cc
index 116dfbd8a0..e3271db2eb 100644
--- a/gtk2_ardour/stereo_panner.cc
+++ b/gtk2_ardour/stereo_panner.cc
@@ -22,6 +22,7 @@
 #include <cmath>
 
 #include <gtkmm/window.h>
+#include <pangomm/layout.h>
 
 #include "pbd/controllable.h"
 #include "pbd/compose.h"
@@ -57,6 +58,9 @@ static const int top_step = 2;
 StereoPanner::ColorScheme StereoPanner::colors[3];
 bool StereoPanner::have_colors = false;
 
+Pango::AttrList StereoPanner::panner_font_attributes;
+bool            StereoPanner::have_font = false;
+
 using namespace ARDOUR;
 
 StereoPanner::StereoPanner (boost::shared_ptr<PannerShell> p)
@@ -79,6 +83,17 @@ StereoPanner::StereoPanner (boost::shared_ptr<PannerShell> p)
 		set_colors ();
 		have_colors = true;
 	}
+	if (!have_font) {
+		Pango::FontDescription font;
+		Pango::AttrFontDesc* font_attr;
+		font = Pango::FontDescription ("ArdourMono");
+		font.set_weight (Pango::WEIGHT_BOLD);
+		font.set_size(9 * PANGO_SCALE);
+		font_attr = new Pango::AttrFontDesc (Pango::Attribute::create_attr_font_desc (font));
+		panner_font_attributes.change(*font_attr);
+		delete font_attr;
+		have_font = true;
+	}
 
 	position_control->Changed.connect (connections, invalidator(*this), boost::bind (&StereoPanner::value_change, this), gui_context());
 	width_control->Changed.connect (connections, invalidator(*this), boost::bind (&StereoPanner::value_change, this), gui_context());
@@ -124,14 +139,17 @@ StereoPanner::on_expose_event (GdkEventExpose*)
 	Glib::RefPtr<Gdk::Window> win (get_window());
 	Glib::RefPtr<Gdk::GC> gc (get_style()->get_base_gc (get_state()));
 	Cairo::RefPtr<Cairo::Context> context = get_window()->create_cairo_context();
+	Glib::RefPtr<Pango::Layout> layout = Pango::Layout::create(get_pango_context());
+	layout->set_attributes (panner_font_attributes);
 
+	int tw, th;
 	int width, height;
-	double pos = position_control->get_value (); /* 0..1 */
-	double swidth = width_control->get_value (); /* -1..+1 */
-	double fswidth = fabs (swidth);
+	const double pos = position_control->get_value (); /* 0..1 */
+	const double swidth = width_control->get_value (); /* -1..+1 */
+	const double fswidth = fabs (swidth);
+	const double corner_radius = 5.0;
 	uint32_t o, f, t, b, r;
 	State state;
-	const double corner_radius = 5.0;
 
 	width = get_width();
 	height = get_height ();
@@ -162,7 +180,8 @@ StereoPanner::on_expose_event (GdkEventExpose*)
 
 	context->set_source_rgba (UINT_RGBA_R_FLT(b), UINT_RGBA_G_FLT(b), UINT_RGBA_B_FLT(b), UINT_RGBA_A_FLT(b));
 	cairo_rectangle (context->cobj(), 0, 0, width, height);
-	context->fill ();
+	context->fill_preserve ();
+	context->clip();
 
 	/* the usable width is reduced from the real width, because we need space for
 	   the two halves of LR boxes that will extend past the actual left/right
@@ -181,17 +200,15 @@ StereoPanner::on_expose_event (GdkEventExpose*)
 		context->translate (1.0, 0.0);
 	}
 
-	double center = (lr_box_size/2.0) + (usable_width * pos);
-	const double pan_spread = (fswidth * usable_width)/2.0;
 	const double half_lr_box = lr_box_size/2.0;
-	int left;
-	int right;
+	const double center = rint(half_lr_box + (usable_width * pos));
+	const double pan_spread = rint((fswidth * (usable_width-1.0))/2.0);
+	const double left  = center - pan_spread;
+	const double right = center + pan_spread;
 
-	left = center - pan_spread;  // center of left box
-	right = center + pan_spread; // center of right box
+	printf("L %.2f  R %.2f  PW:%.2f\n", left, right, pan_spread);
 
 	/* center line */
-
 	context->set_line_width (1.0);
 	context->move_to ((usable_width + lr_box_size)/2.0, 0);
 	context->rel_line_to (0, height);
@@ -199,67 +216,64 @@ StereoPanner::on_expose_event (GdkEventExpose*)
 	context->stroke ();
 
 	/* compute & draw the line through the box */
-
 	context->set_line_width (2);
 	context->set_source_rgba (UINT_RGBA_R_FLT(o), UINT_RGBA_G_FLT(o), UINT_RGBA_B_FLT(o), UINT_RGBA_A_FLT(o));
-	context->move_to (left, top_step+(pos_box_size/2.0)+step_down);
-	context->line_to (left, top_step+(pos_box_size/2.0));
-	context->line_to (right, top_step+(pos_box_size/2.0));
-	context->line_to (right, top_step+(pos_box_size/2.0) + step_down);
+	context->move_to (left,  top_step + (pos_box_size/2.0) + step_down + 1.0);
+	context->line_to (left,  top_step + (pos_box_size/2.0));
+	context->line_to (right, top_step + (pos_box_size/2.0));
+	context->line_to (right, top_step + (pos_box_size/2.0) + step_down + 1.0);
 	context->stroke ();
 
-	/* left box */
-
-	rounded_rectangle (context, left - half_lr_box,
-	                   half_lr_box+step_down,
-	                   lr_box_size, lr_box_size, corner_radius);
-	context->set_source_rgba (UINT_RGBA_R_FLT(o), UINT_RGBA_G_FLT(o), UINT_RGBA_B_FLT(o), UINT_RGBA_A_FLT(o));
-	context->stroke_preserve ();
-	context->set_source_rgba (UINT_RGBA_R_FLT(f), UINT_RGBA_G_FLT(f), UINT_RGBA_B_FLT(f), UINT_RGBA_A_FLT(f));
-	context->fill ();
-
-	/* add text */
-
-	context->move_to (left - half_lr_box + 3,
-	                  (lr_box_size/2) + step_down + 13);
-	context->select_font_face ("sans-serif", Cairo::FONT_SLANT_NORMAL, Cairo::FONT_WEIGHT_BOLD);
+	context->set_line_width (1.0);
 
+	/* left box */
 	if (state != Mono) {
+		rounded_rectangle (context, left - half_lr_box,
+				half_lr_box+step_down,
+				lr_box_size, lr_box_size, corner_radius);
+		context->set_source_rgba (UINT_RGBA_R_FLT(f), UINT_RGBA_G_FLT(f), UINT_RGBA_B_FLT(f), UINT_RGBA_A_FLT(f));
+		context->fill_preserve();
+		context->set_source_rgba (UINT_RGBA_R_FLT(o), UINT_RGBA_G_FLT(o), UINT_RGBA_B_FLT(o), UINT_RGBA_A_FLT(o));
+		context->stroke();
+
+		/* add text */
 		context->set_source_rgba (UINT_RGBA_R_FLT(t), UINT_RGBA_G_FLT(t), UINT_RGBA_B_FLT(t), UINT_RGBA_A_FLT(t));
 		if (swidth < 0.0) {
-			context->show_text (_("R"));
+			layout->set_text (_("R"));
 		} else {
-			context->show_text (_("L"));
+			layout->set_text (_("L"));
 		}
+		layout->get_pixel_size(tw, th);
+		context->move_to (rint(left - tw/2), rint(lr_box_size + step_down - th/2));
+		pango_cairo_show_layout (context->cobj(), layout->gobj());
 	}
 
 	/* right box */
-
 	rounded_rectangle (context, right - half_lr_box,
-	                   half_lr_box+step_down,
-	                   lr_box_size, lr_box_size, corner_radius);
-	context->set_source_rgba (UINT_RGBA_R_FLT(o), UINT_RGBA_G_FLT(o), UINT_RGBA_B_FLT(o), UINT_RGBA_A_FLT(o));
-	context->stroke_preserve ();
+			half_lr_box+step_down,
+			lr_box_size, lr_box_size, corner_radius);
 	context->set_source_rgba (UINT_RGBA_R_FLT(f), UINT_RGBA_G_FLT(f), UINT_RGBA_B_FLT(f), UINT_RGBA_A_FLT(f));
-	context->fill ();
+	context->fill_preserve();
+	context->set_source_rgba (UINT_RGBA_R_FLT(o), UINT_RGBA_G_FLT(o), UINT_RGBA_B_FLT(o), UINT_RGBA_A_FLT(o));
+	context->stroke();
 
 	/* add text */
-
-	context->move_to (right - half_lr_box + 3, (lr_box_size/2)+step_down + 13);
 	context->set_source_rgba (UINT_RGBA_R_FLT(t), UINT_RGBA_G_FLT(t), UINT_RGBA_B_FLT(t), UINT_RGBA_A_FLT(t));
 
 	if (state == Mono) {
-		context->show_text (_("M"));
+		layout->set_text (_("M"));
 	} else {
 		if (swidth < 0.0) {
-			context->show_text (_("L"));
+			layout->set_text (_("L"));
 		} else {
-			context->show_text (_("R"));
+			layout->set_text (_("R"));
 		}
 	}
+	layout->get_pixel_size(tw, th);
+	context->move_to (rint(right - tw/2), rint(lr_box_size + step_down - th/2));
+	pango_cairo_show_layout (context->cobj(), layout->gobj());
 
 	/* draw the central box */
-
 	context->set_line_width (2.0);
 	context->move_to (center + (pos_box_size/2.0), top_step); /* top right */
 	context->rel_line_to (0.0, pos_box_size); /* lower right */