TextureViewer.cpp

#include "TextureViewer.h"

#define SCROLL_SCALE_FACTOR 1.1

TextureViewer::TextureViewer(BaseObjectType* cobject, const Glib::RefPtr<Gtk::Builder>& refGlade)
	: Glib::ObjectBase("TextureViewer"),
	  Gtk::DrawingArea(cobject){
	pixbufValid = false;
	width = 0;
	height = 0;
	scale = 1.0f;
	x = 0;
	y = 0;
	motionLastX = 0;
	motionLastY = 0;
	add_events(Gdk::EventMask::SCROLL_MASK);
	add_events(Gdk::EventMask::BUTTON_MOTION_MASK);
	add_events(Gdk::EventMask::BUTTON_PRESS_MASK);
	add_events(Gdk::EventMask::BUTTON_RELEASE_MASK);
	signal_button_press_event().connect([this] (GdkEventButton* btn) -> bool{
		motionLastX = btn->x;
		motionLastY = btn->y;
		return false;
	});
	signal_button_release_event().connect([this] (GdkEventButton* btn) -> bool{
		return false;
	});
	signal_motion_notify_event().connect([this] (GdkEventMotion* motion) -> bool{

		if(motion->x - motionLastX != 0){
			x += (motion->x - motionLastX) / scale;
		}
		if(motion->y - motionLastY != 0){
			y += (motion->y - motionLastY) / scale;
		}
		motionLastX = motion->x;
		motionLastY = motion->y;

		queue_draw();
		return false;
	});
	signal_scroll_event().connect([this] (GdkEventScroll* scroll) -> bool{
		double scaleOld = scale;
		if(scroll->direction == GdkScrollDirection::GDK_SCROLL_UP){
			scale *= SCROLL_SCALE_FACTOR;
		}

		if(scroll->direction == GdkScrollDirection::GDK_SCROLL_DOWN){
			if(scale > 0.1){
				scale *= (1.0/SCROLL_SCALE_FACTOR);
			}
		}

		double dX = (scroll->x * (scale / scaleOld)) - scroll->x;	// new position - old position
		double dY = (scroll->y * (scale / scaleOld)) - scroll->y;
		x -= dX / scaleOld;
		y -= dY / scaleOld;

		queue_draw();
		// looks like this isn't happening for me, not sure about other systems
		/*if(scroll->direction == GDK_SCROLL_SMOOTH){
			double dx = scroll->delta_x;
			double dy = scroll->delta_y;
		}*/
		return false;
	});
}

TextureViewer::~TextureViewer(){

}

bool TextureViewer::on_draw(const Cairo::RefPtr<Cairo::Context>& cr){

	int totalWidth = get_allocated_width();
	int totalHeight = get_allocated_height();

	int scale = Pango::SCALE;

	if(pixbufValid){

		// check x and y to prevent the image being shoved outside the viewport completely

		double maxX = totalWidth / this->scale;
		double maxY = totalHeight / this->scale;
		double minX = -width;
		double minY = -height;

		if(x > maxX) x = maxX;
		if(y > maxY) y = maxY;
		if(x < minX) x = minX;
		if(y < minY) y = minY;

		cr->scale(this->scale, this->scale);
		Gdk::Cairo::set_source_pixbuf(cr, pixbuf, x, y);
		cr->move_to(x, y);
		cr->paint();
	} else {
		// Error message
		Pango::FontDescription h1font;
		//h1font.set_family("Monospace");
		h1font.set_weight(Pango::WEIGHT_BOLD);
		h1font.set_absolute_size(30000);
		auto mainMessageLayout = create_pango_layout("No Texture to show!");
		mainMessageLayout->set_font_description(h1font);

		Pango::FontDescription pfont;
		//pfont.set_family("Monospace");
		pfont.set_weight(Pango::WEIGHT_MEDIUM);
		pfont.set_size(16*scale);
		auto subTextLayout = create_pango_layout("See log for details.\nPlease include Bitmap Path and Format in bug reports!");
		subTextLayout->set_font_description(pfont);
		subTextLayout->set_alignment(Pango::ALIGN_CENTER);

		int h1_height, h1_width;
		int p_height, p_width;
		mainMessageLayout->get_pixel_size(h1_width, h1_height);
		subTextLayout->get_pixel_size(p_width, p_height);
		Gdk::RGBA colour;
		colour = get_style_context()->get_color(Gtk::STATE_FLAG_INSENSITIVE);

		cr->set_source_rgb(colour.get_red(), colour.get_green(), colour.get_blue());

		// for the main Message.
		// vertically, both layouts get centered together
		cr->move_to((totalWidth - h1_width) / 2, (totalHeight - h1_height - p_height) / 2);
		mainMessageLayout->show_in_cairo_context(cr);

		// subtext, same thing
		cr->move_to((totalWidth - p_width) / 2, ((totalHeight - h1_height - p_height) / 2 ) + h1_height);
		subTextLayout->show_in_cairo_context(cr);
	}

	return true;
}