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basicwin
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predproc
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basicwin.c
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C/C++ Source or Header
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1989-11-27
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10KB
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352 lines
/*
* Copyright 1989 O'Reilly and Associates, Inc.
* See ../Copyright for complete rights and liability information.
*/
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <stdio.h>
#include "../bitmaps/icon_bitmap"
#define BITMAPDEPTH 1
#define SMALL 1
#define OK 0
#define BUF_SIZE 2000
/* These are used as arguments to nearly every Xlib routine, so it saves
* routine arguments to declare them global. If there were
* additional source files, they would be declared extern there. */
Display *display;
int screen;
void main(argc, argv)
int argc;
char **argv;
{
Window win;
unsigned int width, height, x = 0, y = 0; /* window size and position */
unsigned int border_width = 4; /* four pixels */
unsigned int display_width, display_height;
char *window_name = "basicwin";
char *icon_name = "";
Pixmap icon_pixmap;
XSizeHints size_hints;
XEvent report;
GC gc;
XFontStruct *font_info;
char *display_name = NULL;
int window_size = 0; /* OK, or too SMALL to display contents */
int root_x, root_y;
Window root, child;
unsigned int keys_buttons;
Window wint;
XPoint points[BUF_SIZE];
int index = 0;
int pos_x, pos_y;
int prev_x, prev_y;
GC gcx;
Bool predproc();
static char *stuff = "do this or that";
/* connect to X server */
if ( (display=XOpenDisplay(display_name)) == NULL )
{
(void) fprintf( stderr, "basicwin: cannot connect to X server %s\n", XDisplayName(display_name));
exit( -1 );
}
/* get screen size from display structure macro */
screen = DefaultScreen(display);
display_width = DisplayWidth(display, screen);
display_height = DisplayHeight(display, screen);
/* note that x and y are 0, since the default position of the window
* is the top left corner of the root. This is fine since the window
* manager often allows the user to position the window before mapping it. */
/* size window with enough room for text */
width = display_width/3, height = display_height/4;
/* create opaque window */
win = XCreateSimpleWindow(display, RootWindow(display,screen), x, y, width, height, border_width, BlackPixel(display,
screen), WhitePixel(display,screen));
wint = XCreateSimpleWindow(display, win, 20, 20, 50, 50, border_width, BlackPixel(display,
screen), WhitePixel(display,screen));
/* Create pixmap of depth 1 (bitmap) for icon */
icon_pixmap = XCreateBitmapFromData(display, win, icon_bitmap_bits, icon_bitmap_width, icon_bitmap_height);
/* Set resize hints */
size_hints.flags = PPosition | PSize | PMinSize;
size_hints.x = x;
size_hints.y = y;
size_hints.width = width;
size_hints.height = height;
size_hints.min_width = 300;
size_hints.min_height = 200;
/* set Properties for window manager (always before mapping) */
XSetStandardProperties(display, win, window_name, icon_name,
icon_pixmap, argv, argc, &size_hints);
/* Select event types wanted */
XSelectInput(display, win, ExposureMask | KeyPressMask | ButtonPressMask | StructureNotifyMask);
XSelectInput(display, wint, ExposureMask | PointerMotionMask | PointerMotionHintMask);
load_font(&font_info);
/* create GC for text and drawing */
getGC(win, &gc, font_info);
gcx = XCreateGC(display, win, 0, NULL);
XSetFunction(display, gcx, GXxor);
XSetForeground(display, gcx,
WhitePixel(display, screen)^BlackPixel(display, screen));
/* Display window */
XMapWindow(display, win);
XMapWindow(display, wint);
/* get events, use first to display text and graphics */
while (1) {
XIfEvent(display, &report, predproc, stuff);
switch (report.type) {
case MotionNotify:
printf("got a motion event\n");
if (!XQueryPointer(display, report.xmotion.window,
&root, &child, &root_x, &root_y, &pos_x,
&pos_y, &keys_buttons))
/* pointer is on other screen */
break;
if (index != 0)
XDrawLine(display, wint, gcx, prev_x, prev_y,
pos_x, pos_y);
if (index < BUF_SIZE) {
points[index].x = pos_x;
points[index].y = pos_y;
index++;
}
prev_x = pos_x;
prev_y = pos_y;
break;
case Expose:
printf("got expose event\n");
if (report.xexpose.window == wint) {
while (XCheckTypedWindowEvent(display, wint, Expose, &report));
if (index != 0)
XDrawLines(display, wint, gcx, points, index, CoordModeOrigin);
}
else {
while (XCheckTypedWindowEvent(display, win, Expose, &report));
if (window_size == SMALL)
TooSmall(win, gc, font_info);
else {
/* place text in window */
place_text(win, gc, font_info, width, height);
/* place graphics in window, */
place_graphics(win, gc, width, height);
}
}
break;
case ConfigureNotify:
printf("got configure event\n");
/* window has been resized, change width and
* height to send to place_text and place_graphics
* in next Expose */
width = report.xconfigure.width;
height = report.xconfigure.height;
if ((width < size_hints.min_width) || (height < size_hints.min_height))
window_size = SMALL;
else
window_size = OK;
break;
case ButtonPress:
case KeyPress:
XUnloadFont(display, font_info->fid);
XFreeGC(display, gc);
XCloseDisplay(display);
exit(1);
default:
/* all events selected by StructureNotifyMask
* except ConfigureNotify are thrown away here,
* since nothing is done with them */
break;
} /* end switch */
} /* end while */
}
getGC(win, gc, font_info)
Window win;
GC *gc;
XFontStruct *font_info;
{
unsigned long valuemask = 0; /* ignore XGCvalues and use defaults */
XGCValues values;
unsigned int line_width = 6;
int line_style = LineOnOffDash;
int cap_style = CapRound;
int join_style = JoinRound;
int dash_offset = 0;
static char dash_list[] = {12, 24};
int list_length = 2;
/* Create default Graphics Context */
*gc = XCreateGC(display, win, valuemask, &values);
/* specify font */
XSetFont(display, *gc, font_info->fid);
/* specify black foreground since default may be white on white */
XSetForeground(display, *gc, BlackPixel(display,screen));
/* set line attributes */
XSetLineAttributes(display, *gc, line_width, line_style, cap_style, join_style);
/* set dashes to be line_width in length */
XSetDashes(display, *gc, dash_offset, dash_list, list_length);
}
load_font(font_info)
XFontStruct **font_info;
{
char *fontname = "9x15";
/* Access font */
if ((*font_info = XLoadQueryFont(display,fontname)) == NULL)
{
(void) fprintf( stderr, "Basic: Cannot open 9x15 font\n");
exit( -1 );
}
}
place_text(win, gc, font_info, win_width, win_height)
Window win;
GC gc;
XFontStruct *font_info;
unsigned int win_width, win_height;
{
int y = 20; /* offset from corner of window*/
char *string1 = "Hi! I'm a window, who are you?";
char *string2 = "To terminate program; Press any key";
char *string3 = "or button while in this window.";
char *string4 = "Screen Dimensions:";
int len1, len2, len3, len4;
int width1, width2, width3;
char cd_height[50], cd_width[50], cd_depth[50];
int font_height;
int initial_y_offset, x_offset;
/* need length for both XTextWidth and XDrawString */
len1 = strlen(string1);
len2 = strlen(string2);
len3 = strlen(string3);
/* get string widths for centering */
width1 = XTextWidth(font_info, string1, len1);
width2 = XTextWidth(font_info, string2, len2);
width3 = XTextWidth(font_info, string3, len3);
/* output text, centered on each line */
XDrawString(display,win,gc,(win_width - width1)/2,y,string1,len1);
XDrawString(display,win,gc,(win_width - width2)/2, (int)(win_height - 35),string2,len2);
XDrawString(display,win,gc,(win_width - width3)/2, (int)(win_height - 15),string3,len3);
/* copy numbers into string variables */
(void) sprintf(cd_height, " Height - %d pixels", DisplayHeight(display,screen));
(void) sprintf(cd_width, " Width - %d pixels", DisplayWidth(display,screen));
(void) sprintf(cd_depth, " Depth - %d plane(s)", DefaultDepth(display, screen));
/* reuse these for same purpose */
len4 = strlen(string4);
len1 = strlen(cd_height);
len2 = strlen(cd_width);
len3 = strlen(cd_depth);
font_height = font_info->max_bounds.ascent + font_info->max_bounds.descent;
/* To center strings vertically, we place the first string
* so that the top of it is two font_heights above the center
* of the window. Since the baseline of the string is what we
* need to locate for XDrawString, and the baseline is one
* font_info->max_bounds.ascent below the top of the chacter,
* the final offset of the origin up from the center of the
* window is one font_height + one descent. */
initial_y_offset = win_height/2 - font_height - font_info->max_bounds.descent;
x_offset = (int) win_width/4;
XDrawString(display, win, gc, x_offset, (int) initial_y_offset, string4,len4);
XDrawString(display, win, gc, x_offset, (int) initial_y_offset + font_height,cd_height,len1);
XDrawString(display, win, gc, x_offset, (int) initial_y_offset + 2 * font_height,cd_width,len2);
XDrawString(display, win, gc, x_offset, (int) initial_y_offset + 3 * font_height,cd_depth,len3);
}
place_graphics(win, gc, window_width, window_height)
Window win;
GC gc;
unsigned int window_width, window_height;
{
int x, y;
int width, height;
height = window_height/2;
width = 3 * window_width/4;
x = window_width/2 - width/2; /* center */
y = window_height/2 - height/2;
XDrawRectangle(display, win, gc, x, y, width, height);
}
TooSmall(win, gc, font_info)
Window win;
GC gc;
XFontStruct *font_info;
{
char *string1 = "Too Small";
int y_offset, x_offset;
y_offset = font_info->max_bounds.ascent + 2;
x_offset = 2;
/* output text, centered on each line */
XDrawString(display, win, gc, x_offset, y_offset, string1, strlen(string1));
}
Bool predproc(display, event, arg)
Display *display;
XEvent *event;
char *arg;
{
printf("main passed \"%s\" to predicate procedure.\n", arg);
switch (event->type) {
case Expose:
case MotionNotify:
case ConfigureNotify:
case KeyPress:
return(True);
break;
case ButtonPress:
case ButtonRelease:
if (event->xbutton.button == Button1)
return(True);
else
return(False);
break;
default:
break;/* many *Notify event types handled here */
}
}