From a380303d852a3ad3f9b73ccbfbec4cf7f118123e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 21 Jan 2014 23:00:16 +0200
Subject: [PATCH] Properly account for margins in sliders

---
 source/hslider.cpp | 10 ++++++++--
 source/hslider.h   |  3 +++
 source/slider.cpp  | 11 ++++++++---
 source/slider.h    |  1 +
 source/vslider.cpp | 10 ++++++++--
 source/vslider.h   |  3 +++
 6 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/source/hslider.cpp b/source/hslider.cpp
index 4fecfa4..2af6f5a 100644
--- a/source/hslider.cpp
+++ b/source/hslider.cpp
@@ -8,7 +8,8 @@
 namespace Msp {
 namespace GLtk {
 
-HSlider::HSlider()
+HSlider::HSlider():
+	total_margin(0)
 { }
 
 void HSlider::autosize_special(const Part &part, Geometry &ageom) const
@@ -63,7 +64,7 @@ void HSlider::pointer_motion(int x, int)
 
 void HSlider::on_geometry_change()
 {
-	drag_area_size = geom.w-slider_size;
+	drag_area_size = geom.w-total_margin;
 }
 
 void HSlider::on_style_change()
@@ -72,7 +73,12 @@ void HSlider::on_style_change()
 		return;
 
 	if(const Part *slider_part = style->get_part("slider"))
+	{
 		slider_size = slider_part->get_geometry().w;
+		const Sides &margin = slider_part->get_margin();
+		drag_area_offset = margin.left;
+		total_margin = margin.left+margin.right;
+	}
 
 	on_geometry_change();
 }
diff --git a/source/hslider.h b/source/hslider.h
index f0cf8d3..0d840fe 100644
--- a/source/hslider.h
+++ b/source/hslider.h
@@ -12,6 +12,9 @@ the current value of the widget.
 */
 class HSlider: public Slider
 {
+private:
+	unsigned total_margin;
+
 public:
 	HSlider();
 
diff --git a/source/slider.cpp b/source/slider.cpp
index 15621db..1e763c6 100644
--- a/source/slider.cpp
+++ b/source/slider.cpp
@@ -10,6 +10,7 @@ Slider::Slider():
 	step(0.1),
 	dragging(false),
 	drag_area_size(0),
+	drag_area_offset(0),
 	slider_size(1)
 { }
 
@@ -49,13 +50,17 @@ void Slider::set_step(double s)
 
 void Slider::click(int p)
 {
-	int sp = static_cast<int>(drag_area_size*(value-min)/(max-min));
+	p -= drag_area_offset;
+	if(p<0 || p>=static_cast<int>(drag_area_size))
+		return;
+
+	int sp = static_cast<int>((drag_area_size-slider_size)*(value-min)/(max-min));
 	if(p<sp)
 		set_value(value-step*10);
 	else if(p>=static_cast<int>(sp+slider_size))
 		set_value(value+step*10);
 	else
-		start_drag(p);
+		start_drag(drag_area_offset+p);
 }
 
 void Slider::start_drag(int p)
@@ -69,7 +74,7 @@ void Slider::start_drag(int p)
 void Slider::drag(int p)
 {
 	if(max>min)
-		set_value(drag_start_value+(p-drag_start_pos)*(max-min)/drag_area_size);
+		set_value(drag_start_value+(p-drag_start_pos)*(max-min)/(drag_area_size-slider_size));
 }
 
 void Slider::end_drag()
diff --git a/source/slider.h b/source/slider.h
index a239576..a95a6a5 100644
--- a/source/slider.h
+++ b/source/slider.h
@@ -32,6 +32,7 @@ protected:
 	double drag_start_pos;
 	double drag_start_value;
 	unsigned drag_area_size;
+	unsigned drag_area_offset;
 	unsigned slider_size;
 
 	Slider();
diff --git a/source/vslider.cpp b/source/vslider.cpp
index 4776e67..6bc1553 100644
--- a/source/vslider.cpp
+++ b/source/vslider.cpp
@@ -8,7 +8,8 @@
 namespace Msp {
 namespace GLtk {
 
-VSlider::VSlider()
+VSlider::VSlider():
+	total_margin(0)
 { }
 
 void VSlider::autosize_special(const Part &part, Geometry &ageom) const
@@ -63,7 +64,7 @@ void VSlider::pointer_motion(int, int y)
 
 void VSlider::on_geometry_change()
 {
-	drag_area_size = geom.h-slider_size;
+	drag_area_size = geom.h-total_margin;
 }
 
 void VSlider::on_style_change()
@@ -72,7 +73,12 @@ void VSlider::on_style_change()
 		return;
 
 	if(const Part *slider_part = style->get_part("slider"))
+	{
 		slider_size = slider_part->get_geometry().h;
+		const Sides &margin = slider_part->get_margin();
+		drag_area_offset = margin.bottom;
+		total_margin = margin.bottom+margin.top;
+	}
 
 	on_geometry_change();
 }
diff --git a/source/vslider.h b/source/vslider.h
index 987d83a..6086d3f 100644
--- a/source/vslider.h
+++ b/source/vslider.h
@@ -8,6 +8,9 @@ namespace GLtk {
 
 class VSlider: public Slider
 {
+private:
+	unsigned total_margin;
+
 public:
 	VSlider();
 
-- 
2.43.0