paint: add drawing program from 9front (#112)

Paint first appeared in 9front. The 9front license is reproduced
in the related source files - the original repository is located at
https://code.9front.org/hg/plan9front.

1 files changed, 258 insertions, 0 deletions

diff --git a/src/cmd/paint/eenter.c b/src/cmd/paint/eenter.c
new file mode 100644
index 00000000..6645820c
--- /dev/null
+++ b/src/cmd/paint/eenter.c
@@ -0,0 +1,258 @@
+/*
+This code was taken from 9front repository (https://code.9front.org/hg/plan9front).
+It is subject to license from 9front, below is a reproduction of the license.
+
+Copyright (c) 20XX 9front
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <event.h>
+#include <keyboard.h>
+
+/* additional keyboard codes needed - defined here to avoid API change */
+enum {
+	Spec=   0xF800,
+	Knack=  0x15,
+	Ksoh=   0x01,
+	Kenq=   0x05,
+	Ketb=   0x17
+};
+
+int
+eenter(char *ask, char *buf, int len, Mouse *m)
+{
+	int done, down, tick, n, h, w, l, i;
+	Image *b, *save, *backcol, *bordcol;
+	Point p, o, t;
+	Rectangle r, sc;
+	Event ev;
+	Rune k;
+
+	o = screen->r.min;
+	backcol = allocimagemix(display, DPurpleblue, DWhite);
+	bordcol = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DPurpleblue);
+	if(backcol == nil || bordcol == nil)
+		return -1;
+
+	while(ecankbd())
+		ekbd();
+
+	if(m) o = m->xy;
+
+	if(buf && len > 0)
+		n = strlen(buf);
+	else {
+		buf = nil;
+		len = 0;
+		n = 0;
+	}
+
+	k = -1;
+	tick = n;
+	save = nil;
+	done = down = 0;
+
+	p = stringsize(font, " ");
+	h = p.y;
+	w = p.x;
+
+	b = screen;
+	sc = b->clipr;
+	replclipr(b, 0, b->r);
+
+	while(!done){
+		p = stringsize(font, buf ? buf : "");
+		if(ask && ask[0]){
+			if(buf) p.x += w;
+			p.x += stringwidth(font, ask);
+		}
+		r = rectaddpt(insetrect(Rpt(ZP, p), -4), o);
+		p.x = 0;
+		r = rectsubpt(r, p);
+
+		p = ZP;
+		if(r.min.x < screen->r.min.x)
+			p.x = screen->r.min.x - r.min.x;
+		if(r.min.y < screen->r.min.y)
+			p.y = screen->r.min.y - r.min.y;
+		r = rectaddpt(r, p);
+		p = ZP;
+		if(r.max.x > screen->r.max.x)
+			p.x = r.max.x - screen->r.max.x;
+		if(r.max.y > screen->r.max.y)
+			p.y = r.max.y - screen->r.max.y;
+		r = rectsubpt(r, p);
+
+		r = insetrect(r, -2);
+		if(save == nil){
+			save = allocimage(display, r, b->chan, 0, DNofill);
+			if(save == nil){
+				n = -1;
+				break;
+			}
+			draw(save, r, b, nil, r.min);
+		}
+		draw(b, r, backcol, nil, ZP);
+		border(b, r, 2, bordcol, ZP);
+		p = addpt(r.min, Pt(6, 6));
+		if(ask && ask[0]){
+			p = string(b, p, bordcol, ZP, font, ask);
+			if(buf) p.x += w;
+		}
+		if(buf){
+			t = p;
+			p = stringn(b, p, display->black, ZP, font, buf, utfnlen(buf, tick));
+			draw(b, Rect(p.x-1, p.y, p.x+2, p.y+3), display->black, nil, ZP);
+			draw(b, Rect(p.x, p.y, p.x+1, p.y+h), display->black, nil, ZP);
+			draw(b, Rect(p.x-1, p.y+h-3, p.x+2, p.y+h), display->black, nil, ZP);
+			p = string(b, p, display->black, ZP, font, buf+tick);
+		}
+		flushimage(display, 1);
+
+nodraw:
+		i = Ekeyboard;
+		if(m != nil)
+			i |= Emouse;
+
+		replclipr(b, 0, sc);
+		i = eread(i, &ev);
+
+		/* screen might have been resized */
+		if(b != screen || !eqrect(screen->clipr, sc)){
+			freeimage(save);
+			save = nil;
+		}
+		b = screen;
+		sc = b->clipr;
+		replclipr(b, 0, b->r);
+
+		switch(i){
+		default:
+			done = 1;
+			n = -1;
+			break;
+		case Ekeyboard:
+			k = ev.kbdc;
+			if(buf == nil || k == Keof || k == '\n'){
+				done = 1;
+				break;
+			}
+			if(k == Knack || k == Kesc){
+				done = !n;
+				buf[n = tick = 0] = 0;
+				break;
+			}
+			if(k == Ksoh || k == Khome){
+				tick = 0;
+				continue;
+			}
+			if(k == Kenq || k == Kend){
+				tick = n;
+				continue;
+			}
+			if(k == Kright){
+				if(tick < n)
+					tick += chartorune(&k, buf+tick);
+				continue;
+			}
+			if(k == Kleft){
+				for(i = 0; i < n; i += l){
+					l = chartorune(&k, buf+tick);
+					if(i+l >= tick){
+						tick = i;
+						break;
+					}
+				}
+				continue;
+			}
+			if(k == Ketb){
+				while(tick > 0){
+					tick--;
+					if(tick == 0 ||
+					   strchr(" !\"#$%&'()*+,-./:;<=>?@`[\\]^{|}~", buf[tick-1]))
+						break;
+				}
+				buf[n = tick] = 0;
+				break;
+			}
+			if(k == Kbs){
+				if(tick <= 0)
+					continue;
+				for(i = 0; i < n; i += l){
+					l = chartorune(&k, buf+i);
+					if(i+l >= tick){
+						memmove(buf+i, buf+i+l, n - (i+l));
+						buf[n -= l] = 0;
+						tick -= l;
+						break;
+					}
+				}
+				break;
+			}
+			if(k < 0x20 || k == Kdel || (k & 0xFF00) == KF || (k & 0xFF00) == Spec)
+				continue;
+			if((len-n) <= (l = runelen(k)))
+				continue;
+			memmove(buf+tick+l, buf+tick, n - tick);
+			runetochar(buf+tick, &k);
+			buf[n += l] = 0;
+			tick += l;
+			break;
+		case Emouse:
+			*m = ev.mouse;
+			if(!ptinrect(m->xy, r)){
+				down = 0;
+				goto nodraw;
+			}
+			if(m->buttons & 7){
+				down = 1;
+				if(buf && m->xy.x >= (t.x - w)){
+					down = 0;
+					for(i = 0; i < n; i += l){
+						l = chartorune(&k, buf+i);
+						t.x += stringnwidth(font, buf+i, 1);
+						if(t.x > m->xy.x)
+							break;
+					}
+					tick = i;
+				}
+				continue;
+			}
+			done = down;
+			break;
+		}
+		if(save){
+			draw(b, save->r, save, nil, save->r.min);
+			freeimage(save);
+			save = nil;
+		}
+	}
+
+	replclipr(b, 0, sc);
+
+	freeimage(backcol);
+	freeimage(bordcol);
+	flushimage(display, 1);
+
+	return n;
+}
+