Volume 7A: XView Programming Manual

Example F-4. The type_font.c program

/*

* simple_font.c -- very simple program showing how to render text

* using fonts loaded by XView.

*/

#include <ctype.h>

#include <X11/X.h>

#include <X11/Xlib.h>

#include <xview/xview.h>

#include <xview/panel.h>

#include <xview/font.h>

Display *dpy;

GC gc;

XFontStruct *font_info;

main(argc, argv)

int argc;

char *argv[ ];

{

Frame frame;

Panel panel;

Canvas canvas;

XGCValues gcvalues;

Xv_Font font;

void my_event_proc();

extern void exit();

xv_init(XV_INIT_ARGC_PTR_ARGV, &argc, argv, NULL);

frame = (Frame)xv_create(XV_NULL, FRAME,

FRAME_LABEL, argv[0],

NULL);

panel = (Panel)xv_create(frame, PANEL,

PANEL_LAYOUT, PANEL_VERTICAL,

NULL);

xv_create(panel, PANEL_BUTTON,

PANEL_LABEL_STRING, "Quit",

PANEL_NOTIFY_PROC, exit,

NULL);

window_fit(panel);

canvas = (Canvas)xv_create(frame, CANVAS,

XV_WIDTH, 400,

XV_HEIGHT, 200,

CANVAS_X_PAINT_WINDOW, TRUE,

NULL);

xv_set(canvas_paint_window(canvas),

WIN_EVENT_PROC, my_event_proc,

NULL);

window_fit(frame);

dpy = (Display *)xv_get(frame, XV_DISPLAY);

font = (Xv_Font)xv_get(frame, XV_FONT);

font_info = (XFontStruct *)xv_get(font, FONT_INFO);

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Example F-4. The type_font.c program (continued)

gcvalues.font = (Font)xv_get(font, XV_XID);

gcvalues.foreground = BlackPixel(dpy, DefaultScreen(dpy));

gcvalues.background = WhitePixel(dpy, DefaultScreen(dpy));

gcvalues.graphics_exposures = False;

gc = XCreateGC(dpy, RootWindow(dpy, DefaultScreen(dpy)),

GCForeground | GCBackground | GCFont | GCGraphicsExposures, &gcvalues);

xv_main_loop(frame);

}

void

my_event_proc(win, event)

Xv_Window win;

Event *event;

{

static int x = 10, y = 10;

Window xwin = (Window)xv_get(win, XV_XID);

char c;

if (event_is_up(event))

return;

if (event_is_ascii(event)) {

c = (char)event_id(event);

if (c == ’0 || c == ’

’) {

y += font_info->max_bounds.ascent +

font_info->max_bounds.descent;

x = 10;

} else if (c == 7 || c == 127) { /* backspace or delete */

if (x > 10)

x -= XTextWidth(font_info, "m", 1);

/* use XDrawImageString to overwrite previous text */

XDrawImageString(dpy, xwin, gc, x, y, " ", 2);

} else {

XDrawString(dpy, xwin, gc, x, y, &c, 1);

x += XTextWidth(font_info, &c, 1);

}

} else if (event_action(event) == ACTION_SELECT) {

x = event_x(event);

y = event_y(event);

}

}

Example Programs

Example Programs 729

F.5 fonts.c

This program is similar to type_font.c above. However, fonts.c provides an interface for the

user to pick and choose from a subset of the font families and styles available on the X

server. If a font “name” is specified, then the family, style and size choices are ignored.

Using the SELECT button on the canvas window positions the current typing location at the

x,y coordinates of the button-down event. The characters typed are printed in the current

font.

Example F-5. The fonts.c program

/*

* fonts.c -- provide an interface for the user to pick and choose

* between font families and styles known to XView. The program

* provides several panel buttons to choose between font types, and

* a canvas window in which the user can type. The characters typed

* are printed in the current font. If a font "name" is specified,

* then the family, style and size are ignored. Using the SELECT

* button on the canvas window positions the current typing location

* at the x,y coordinates of the button-down event.

*/

#include <ctype.h>

#include <X11/X.h>

#include <X11/Xlib.h>

#include <xview/xview.h>

#include <xview/panel.h>

#include <xview/font.h>

Display *dpy;

GC gc;

XFontStruct *cur_font;

Panel_item family_item, style_item, scale_item, name_item;

int canvas_width;

main(argc, argv)

int argc;

char *argv[ ];

{

Frame frame;

Panel panel;

Canvas canvas;

XGCValues gcvalues;

Xv_Font font;

void change_font();

void my_event_proc(), my_resize_proc();

int change_font_by_name();

extern void exit();

xv_init(XV_INIT_ARGC_PTR_ARGV, &argc, argv, NULL);

frame = (Frame)xv_create(XV_NULL, FRAME,

FRAME_LABEL, argv[0],

FRAME_SHOW_FOOTER, TRUE,

NULL);

730 XView Programming Manual

Example F-5. The fonts.c program (continued)

panel = (Panel)xv_create(frame, PANEL,

PANEL_LAYOUT, PANEL_VERTICAL,

NULL);

(void) xv_create(panel, PANEL_BUTTON,

PANEL_LABEL_STRING, "Quit",

PANEL_NOTIFY_PROC, exit,

NULL);

family_item = (Panel_item)xv_create(panel, PANEL_CHOICE,

PANEL_LABEL_STRING, "Family",

PANEL_LAYOUT, PANEL_HORIZONTAL,

PANEL_DISPLAY_LEVEL, PANEL_CURRENT,

PANEL_CHOICE_STRINGS,

FONT_FAMILY_DEFAULT, FONT_FAMILY_DEFAULT_FIXEDWIDTH,

FONT_FAMILY_LUCIDA, FONT_FAMILY_LUCIDA_FIXEDWIDTH,

FONT_FAMILY_ROMAN, FONT_FAMILY_SERIF, FONT_FAMILY_COUR,

FONT_FAMILY_CMR, FONT_FAMILY_GALLENT,

FONT_FAMILY_OLGLYPH, FONT_FAMILY_OLCURSOR, NULL,

PANEL_NOTIFY_PROC, change_font,

NULL);

style_item = (Panel_item)xv_create(panel, PANEL_CHOICE,

PANEL_LABEL_STRING, "Style",

PANEL_LAYOUT, PANEL_HORIZONTAL,

PANEL_DISPLAY_LEVEL, PANEL_CURRENT,

PANEL_CHOICE_STRINGS,

FONT_STYLE_DEFAULT, FONT_STYLE_NORMAL, FONT_STYLE_BOLD,

FONT_STYLE_ITALIC, FONT_STYLE_BOLD_ITALIC, NULL,

PANEL_NOTIFY_PROC, change_font,

NULL);

scale_item = (Panel_item)xv_create(panel, PANEL_CHOICE,

PANEL_LABEL_STRING, "Scale",

PANEL_LAYOUT, PANEL_HORIZONTAL,

PANEL_DISPLAY_LEVEL, PANEL_CURRENT,

PANEL_CHOICE_STRINGS,

"Small", "Medium", "Large", "X-Large", NULL,

PANEL_NOTIFY_PROC, change_font,

NULL);

name_item = (Panel_item)xv_create(panel, PANEL_TEXT,

PANEL_LABEL_STRING, "Font Name:",

PANEL_LAYOUT, PANEL_HORIZONTAL,

PANEL_VALUE_DISPLAY_LENGTH, 20,

PANEL_NOTIFY_PROC, change_font_by_name,

NULL);

window_fit(panel);

canvas = (Canvas)xv_create(frame, CANVAS,

XV_WIDTH, 400,

XV_HEIGHT, 200,

CANVAS_X_PAINT_WINDOW, TRUE,

CANVAS_RESIZE_PROC, my_resize_proc,

NULL);

xv_set(canvas_paint_window(canvas),

WIN_EVENT_PROC, my_event_proc,

WIN_CONSUME_EVENT, LOC_WINENTER,

NULL);

window_fit(frame);

Example Programs

Example Programs 731

Example F-5. The fonts.c program (continued)

dpy = (Display *)xv_get(frame, XV_DISPLAY);

font = (Xv_Font)xv_get(frame, XV_FONT);

cur_font = (XFontStruct *)xv_get(font, FONT_INFO);

xv_set(frame, FRAME_LEFT_FOOTER, xv_get(font, FONT_NAME), NULL);

gcvalues.font = cur_font->fid;

gcvalues.foreground = BlackPixel(dpy, DefaultScreen(dpy));

gcvalues.background = WhitePixel(dpy, DefaultScreen(dpy));

gcvalues.graphics_exposures = False;

gc = XCreateGC(dpy, RootWindow(dpy, DefaultScreen(dpy)),

GCForeground | GCBackground | GCFont | GCGraphicsExposures,

&gcvalues);

xv_main_loop(frame);

}

void

my_event_proc(win, event)

Xv_Window win;

Event *event;

{

static int x = 10, y = 10;

Window xwin = (Window)xv_get(win, XV_XID);

char c;

if (event_is_up(event))

return;

if (event_is_ascii(event)) {

c = (char)event_action(event);

XDrawString(dpy, xwin, gc, x, y, &c, 1);

/* advance x to next position. If over edge, linewrap */

if ((x += XTextWidth(cur_font, &c, 1)) >= canvas_width) {

y += cur_font->max_bounds.ascent +

cur_font->max_bounds.descent;

x = 10;

}

} else if (event_action(event) == ACTION_SELECT) {

x = event_x(event);

y = event_y(event);

} else if (event_action(event) == LOC_WINENTER)

win_set_kbd_focus(win, xwin);

}

/*

* check resizing so we know how wide to allow the user to type.

*/

void

my_resize_proc(canvas, width, height)

Canvas canvas;

int width, height;

{

canvas_width = width;

}

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