window.cc

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <iostream>
#include <sstream>
#include <cstdlib>
#include <string>
#include <unistd.h>
#include <cmath>
#include "window.h"

using namespace std;

const double pi = std::acos(-1);

Xwindow::Xwindow(int width, int height): width{width}, height{height} {

	d = XOpenDisplay(NULL);
	if (d == NULL) {
		cerr << "Cannot open display" << endl;
		exit(1);
	}
	s = DefaultScreen(d);
	w = XCreateSimpleWindow(d, RootWindow(d, s), 10, 10, width, height, 1,
			BlackPixel(d, s), WhitePixel(d, s));
	XSelectInput(d, w, ExposureMask | KeyPressMask);
	XMapRaised(d, w);

	Pixmap pix = XCreatePixmap(d,w,width,
			height,DefaultDepth(d,DefaultScreen(d)));
	gc = XCreateGC(d, pix, 0,(XGCValues *)0);

	Font thefont = XLoadFont(d, "*-fixed-*-*-*-*-*-*-*-*-*-*-*-*");
	XFlush(d);
	XFlush(d);


	// Set up colours.
	XColor xcolour;
	Colormap cmap;
	char color_vals[11][11] = {"white",  "black", "red",      "green",
		"blue",   "cyan",  "yellow",   "magenta",
		"orange", "brown", "darkgreen"};

	cmap=DefaultColormap(d,DefaultScreen(d));
	for(int i=0; i < 11; ++i) {
		XParseColor(d,cmap,color_vals[i],&xcolour);
		XAllocColor(d,cmap,&xcolour);
		colours[i]=xcolour.pixel;
	}

	XSetForeground(d,gc,colours[Black]);

	// Make window non-resizeable.
	XSizeHints hints;
	hints.flags = (USPosition | PSize | PMinSize | PMaxSize );
	hints.height = hints.base_height = hints.min_height = hints.max_height = height;
	hints.width = hints.base_width = hints.min_width = hints.max_width = width;
	XSetNormalHints(d, w, &hints);

	XSynchronize(d, True);

	XSelectInput(d, w, ExposureMask);
	XFlush(d);
	XEvent event;
	XNextEvent(d, &event); // Hang until the window is ready.
	XSelectInput(d, w, 0);

}

Xwindow::~Xwindow() {
	XFreeGC(d, gc);
	XCloseDisplay(d);
}

void Xwindow::fillRectangle(int x, int y, int width, int height, int colour) {
	XSetForeground(d, gc, colours[colour]);
	XFillRectangle(d, w, gc, x, y, width, height);
	XSetForeground(d, gc, colours[Black]);
}

void Xwindow::fillPolygon(int x, int y, int vertices, int side, int rotate, int colour){
	XPoint* point = new XPoint[vertices];

	point[0] = XPoint{(short int)x, (short int)y};

	double angle = rotate + pi/2;

	for ( int i = 1; i < vertices; ++i ){
		short int X = side * sin(angle);
		short int Y = side * cos(angle);
		point[i] = XPoint{X,Y};
		angle += 2*pi - pi* 2/vertices;
	}

	XSetForeground(d, gc, colours[colour]);
	XFillPolygon(d, w, gc, point, vertices, Convex, CoordModePrevious);
	XSetForeground(d, gc, colours[Black]);

	delete[] point;
}

void Xwindow::drawLine(int x1, int y1, int x2, int y2) {
	    XDrawLine(d, w, gc, x1, y1, x2, y2);
}

void Xwindow::drawArc(int x1, int y1, int width, int height, int sAngle,
                      int eAngle) {
	    XDrawArc(d, w, gc, x1, y1, width/2, height/2, sAngle * 64, eAngle * 64);
}

void Xwindow::fillArc(int x, int y, int width, int height, int angle1,
                      int angle2, int colour) {
	    XSetForeground(d, gc, colours[colour]);
			    XFillArc(d, w, gc, x-width/2, y-height/2, width, height, angle1 * 64, angle2 * 64);
					    XSetForeground(d, gc, colours[Black]);
}

void Xwindow::fillCircle(int x, int y, int di, int colour) {
	    fillArc(x, y, di, di, 0, 360, colour);
}

void Xwindow::drawString(int x, int y, string msg, int colour) {
  XFontStruct * f = XLoadQueryFont(d, "6x13");
	
	printMessage(x, y, msg, colour, *f); 

	// delete f; // causes memory leak
	/* 
	 * Nomair: March, 2020
	 * Will call XFreeFont to deallocate f instead of using
	 * delete even though it uses free and it is considered 
	 * poor practice to mix delete and free.
	 * If issues are reported, the delete line above can
	 * be uncommented and the XFreeFont call below can be
	 * commented.
	 */
	XFreeFont(d,f);
}


void Xwindow::drawStringFont(int x, int y, string msg, string font, int colour) {
  XFontStruct * f = XLoadQueryFont(d, font.c_str());
  
	if ( f == nullptr ){
		f = XLoadQueryFont(d, "6x13");
	}

	printMessage(x, y, msg, colour, *f);
	// delete f; // causes memory leak
	/* 
	 * Nomair: March, 2020
	 * Will call XFreeFont to deallocate f instead of using
	 * delete even though it uses free and it is considered 
	 * poor practice to mix delete and free.
	 * If issues are reported, the delete line above can
	 * be uncommented and the XFreeFont call below can be
	 * commented.
	 */
	XFreeFont(d,f);
}

void Xwindow::drawBigString(int x, int y, string msg, int colour) {
  // Font f = XLoadFont(d, "-*-helvetica-bold-r-normal--*-240-*-*-*-*-*");
  ostringstream name;
  name << "-*-helvetica-bold-r-*-*-*-240-" << width/5 << "-" << height/5 << "-*-*-*-*";

	drawStringFont(x, y, msg, name.str(), colour);
}

void Xwindow::printMessage(int x, int y, const string& msg, int colour, XFontStruct& f){
  XSetForeground(d, gc, colours[colour]);
  XTextItem ti;
  ti.chars = const_cast<char*>(msg.c_str());
  ti.nchars = msg.length();
  ti.delta = 0;
  ti.font = f.fid;
  XDrawText(d, w, gc, x, y, &ti, 1);
  XSetForeground(d, gc, colours[Black]);
  XFlush(d);
}

void Xwindow::showAvailableFonts() {
  int count;
  char** fnts = XListFonts(d, "*", 10000, &count);

  for (int i = 0; i < count; ++i) cout << fnts[i] << endl;
}