1 files changed, 389 insertions, 0 deletions
diff --git a/libs/gtkmm2ext/scroomer.cc b/libs/gtkmm2ext/scroomer.cc
new file mode 100644
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+++ b/libs/gtkmm2ext/scroomer.cc
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+/*
+    Copyright (C) 2008 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 <iostream>
+#include <gtkmm2ext/scroomer.h>
+
+using namespace Gtkmm2ext;
+using namespace Gtk;
+using namespace Gdk;
+using namespace std;
+
+Scroomer::Scroomer(Gtk::Adjustment& adjustment)
+	: adj(adjustment)
+	, handle_size(0)
+	, grab_comp(None) {
+
+	position[TopBase] = 0;
+	position[Handle1] = 0;
+	position[Slider] = 0;
+	position[Handle2] = 0;
+	position[BottomBase] = 0;
+	position[Total] = 0;
+
+	add_events (Gdk::BUTTON_PRESS_MASK |
+		    Gdk::BUTTON_RELEASE_MASK |
+		    Gdk::POINTER_MOTION_MASK |
+		    Gdk::SCROLL_MASK);
+
+	adjustment.signal_value_changed().connect (mem_fun (*this, &Scroomer::adjustment_changed));
+	//adjustment.signal_changed().connect (mem_fun (*this, &Scroomer::adjustment_changed));
+}
+
+Scroomer::~Scroomer() {
+}
+
+bool
+Scroomer::on_motion_notify_event (GdkEventMotion* ev) {
+	double range = adj.get_upper() - adj.get_lower();
+	double pixel2val = range / get_height();
+	double val_at_pointer = ((get_height() - ev->y) * pixel2val) + adj.get_lower();
+	double delta_y = ev->y - grab_y;
+	double half_min_page = min_page_size / 2;
+	double fract = delta_y / position[Total];
+	double scale, temp, zoom;
+	double val, page;
+
+	if(grab_comp == None || grab_comp == Total) {
+		return true;
+	}
+
+	if (ev->window != grab_window) {
+		grab_y = ev->y;
+		grab_window = ev->window;
+		return true;
+	}
+
+	grab_y = ev->y;
+
+	if (ev->state & GDK_CONTROL_MASK) {
+		if (ev->state & GDK_MOD1_MASK) {
+			scale = 0.05;
+		} else {
+			scale = 0.1;
+		}
+	} else {
+		scale = 1.0;
+	}
+
+	fract = min (1.0, fract);
+	fract = max (-1.0, fract);
+	fract = -fract;
+
+	switch(grab_comp) {
+	case TopBase:
+	case BottomBase:
+		unzoomed_val += scale * fract * range;
+		unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
+		unzoomed_val = max(unzoomed_val, adj.get_lower());
+		break;
+	case Slider:
+		unzoomed_val += scale * fract * range;
+		unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
+		unzoomed_val = max(unzoomed_val, adj.get_lower());
+		break;
+	case Handle1:
+		unzoomed_page += scale * fract * range;
+		unzoomed_page = min(unzoomed_page, adj.get_upper() - unzoomed_val);
+		unzoomed_page = max(unzoomed_page, min_page_size);
+		break;
+	case Handle2:
+		temp = unzoomed_val + unzoomed_page;
+		unzoomed_val += scale * fract * range;
+		unzoomed_val = min(unzoomed_val, temp - min_page_size);
+		unzoomed_val = max(unzoomed_val, adj.get_lower());
+
+		unzoomed_page = temp - unzoomed_val;
+		unzoomed_page = max(unzoomed_page, min_page_size);
+		break;
+	default:
+		break;
+	}
+
+	/*
+	 * Then we handle zoom, which is dragging horizontally. We zoom around the area that is
+	 * the current y pointer value, not from the area that was the start of the drag.
+	 * the point of zoom must have the same 
+	 */
+	
+	if(ev->x > get_width()) {
+		zoom = ev->x - get_width();
+		
+		double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
+		double lower = val_at_pointer - (unzoomed_val + half_min_page);
+
+		higher *= zoom / 128;
+		lower *= zoom / 128;
+
+		val = unzoomed_val + lower;
+		page = unzoomed_page - higher - lower;
+
+		page = max(page, min_page_size);
+
+		if(lower < 0) {
+			val = max(val, val_at_pointer - half_min_page);
+		}
+		else if(lower > 0) {
+			val = min(val, val_at_pointer - half_min_page);
+		}
+
+		val = min(val, adj.get_upper() - min_page_size);
+		page = min(page, adj.get_upper() - val);
+	}
+	else if (ev->x < 0) {
+		/* on zoom out increase the page size as well as moving the range towards the mouse pos*/
+		zoom = abs(ev->x);
+
+		/*double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
+		double lower = val_at_pointer - (unzoomed_val + half_min_page);
+
+		higher *= zoom / 128;
+		lower *= zoom / 128;
+
+		val = unzoomed_val + lower;
+		page = unzoomed_page - higher - lower;
+
+		page = max(page, min_page_size);
+
+		if(lower < 0) {
+			val = max(val, val_at_pointer - half_min_page);
+		}
+		else if(lower > 0) {
+			val = min(val, val_at_pointer - half_min_page);
+		}
+
+		val = min(val, adj.get_upper() - min_page_size);
+		page = min(page, adj.get_upper() - val);*/
+
+		val = unzoomed_val;
+		page = unzoomed_page;
+	}
+	else {
+		val = unzoomed_val;
+		page = unzoomed_page;
+	}
+
+	adj.set_page_size(page);
+	
+	if(val == adj.get_value()) {
+		adj.value_changed();
+	}
+	if(val < adj.get_lower()) {
+		adj.value_changed();
+	}
+	else if(val > adj.get_upper()) {
+		adj.value_changed();
+	}
+	else {
+		adj.set_value(val);
+	}
+
+	return true;
+}
+
+bool
+Scroomer::on_button_press_event (GdkEventButton* ev) {
+	if(ev->button == 1) {
+		Component comp = point_in(ev->y);
+
+		if(comp == Total || comp == None) {
+			return false;
+		}
+
+		add_modal_grab();
+		grab_comp = comp;
+		grab_y = ev->y;
+		unzoomed_val = adj.get_value();
+		unzoomed_page = adj.get_page_size();
+		grab_window = ev->window;
+	}
+	return false;
+}
+
+bool
+Scroomer::on_button_release_event (GdkEventButton* ev) {
+	if(grab_comp == None || grab_comp == Total) {
+		return true;
+	}
+
+	if (ev->window != grab_window) {
+		grab_y = ev->y;
+		grab_window = ev->window;
+		return true;
+	}
+
+	if (ev->button != 1) {
+		return true;
+	}
+
+	switch(grab_comp) {
+	case TopBase:
+		break;
+	case Handle1:
+		break;
+	case Slider:
+		break;
+	case Handle2:
+		break;
+	case BottomBase:
+		break;
+	default:
+		break;
+	}
+	
+	grab_comp = None;
+
+	remove_modal_grab();
+	return true;
+}
+
+bool
+Scroomer::on_scroll_event (GdkEventScroll*) {
+	return true;
+}
+
+void
+Scroomer::on_size_allocate (Allocation& a) {
+	Gtk::DrawingArea::on_size_allocate(a);
+
+	position[Total] = a.get_height();
+	set_min_page_size(min_page_size);
+	update();
+}
+
+/*
+ * assumes that x and width are correct, and they will not be altered
+ */
+void
+Scroomer::set_comp_rect(GdkRectangle& r, Component c) const {
+	int index = (int) c;
+
+	switch(c) {
+	case None:
+		return;
+	case Total:
+		r.y = 0;
+		r.height = position[Total];
+		break;
+	default:
+		r.y = position[index];
+		r.height = position[index+1] - position[index];
+		break;
+	}
+}
+
+Scroomer::Component
+Scroomer::point_in(double point) const {
+	for(int i = 0; i < Total; ++i) {
+		if(position[i+1] >= point) {
+			return (Component) i;
+		}
+	}
+
+	return None;
+}
+
+void
+Scroomer::set_min_page_size(double ps) {
+	double coeff = ((double)position[Total]) / (adj.get_upper() - adj.get_lower());
+
+	min_page_size = ps;
+	handle_size = (int) floor((ps * coeff) / 2);
+}
+
+void
+Scroomer::update() {
+	double range = adj.get_upper() - adj.get_lower();
+	//double value = adj.get_value() - adj.get_lower();
+	int height = position[Total];
+	double coeff = ((double) height) / range;
+
+	/* save the old positions to calculate update regions later*/
+	for(int i = Handle1; i < Total; ++i) {
+		old_pos[i] = position[i];
+	}
+
+	position[BottomBase] = (int) floor(height - (adj.get_value() * coeff));
+	position[Handle2] = position[BottomBase] - handle_size;
+
+	position[Handle1] = (int) floor(height - ((adj.get_value() + adj.get_page_size()) * coeff));
+	position[Slider] = position[Handle1] + handle_size;
+}
+
+void
+Scroomer::adjustment_changed() {
+	//cerr << floor(adj.get_value()) << " " << floor(adj.get_value() + adj.get_page_size()) << endl;
+	Gdk::Rectangle rect;
+	Glib::RefPtr<Gdk::Window> win = get_window();
+
+	update();
+
+	if(!win) {
+		return;
+	}
+
+	rect.set_x(0);
+	rect.set_width(get_width());
+
+	if(position[Handle1] < old_pos[Handle1]) {
+		rect.set_y(position[Handle1]);
+		rect.set_height(old_pos[Slider] - position[Handle1]);
+		win->invalidate_rect(rect, false);
+	}
+	else if(position[Handle1] > old_pos[Handle1]) {
+		rect.set_y(old_pos[Handle1]);
+		rect.set_height(position[Slider] - old_pos[Handle1]);
+		win->invalidate_rect(rect, false);
+	}
+
+	if(position[Handle2] < old_pos[Handle2]) {
+		rect.set_y(position[Handle2]);
+		rect.set_height(old_pos[BottomBase] - position[Handle2]);
+		win->invalidate_rect(rect, false);
+	}
+	else if(position[Handle2] > old_pos[Handle2]) {
+		rect.set_y(old_pos[Handle2]);
+		rect.set_height(position[BottomBase] - old_pos[Handle2]);
+		win->invalidate_rect(rect, false);
+	}
+
+	win->process_updates(false);
+}
+
+std::string
+Scroomer::get_comp_name(Component c) {
+	switch(c) {
+	case TopBase:
+		return "TopBase";
+	case Handle1:
+		return "Handle1";
+	case Slider:
+		return "Slider";
+	case Handle2:
+		return "Handle2";
+	case BottomBase:
+		return "BottomBase";
+	case Total:
+		return "Total";
+	case None:
+		return "None";
+	default:
+		return "ERROR";
+	}
+}