ref: 66719fb3ea15351f8860cc6696993357a60ab238
dir: /sys/src/libdraw/emenuhit.c/
#include <u.h> #include <libc.h> #include <draw.h> #include <event.h> enum { Margin = 4, /* outside to text */ Border = 2, /* outside to selection boxes */ Blackborder = 2, /* width of outlining border */ Vspacing = 2, /* extra spacing between lines of text */ Maxunscroll = 25, /* maximum #entries before scrolling turns on */ Nscroll = 20, /* number entries in scrolling part */ Scrollwid = 14, /* width of scroll bar */ Gap = 4, /* between text and scroll bar */ }; static Image *menutxt; static Image *back; static Image *high; static Image *bord; static Image *text; static Image *htext; static void menucolors(void) { /* Main tone is greenish, with negative selection */ back = allocimagemix(display, DPalegreen, DWhite); high = allocimage(display, Rect(0,0,1,1), CMAP8, 1, DDarkgreen); /* dark green */ bord = allocimage(display, Rect(0,0,1,1), CMAP8, 1, DMedgreen); /* not as dark green */ if(back==nil || high==nil || bord==nil) goto Error; text = display->black; htext = back; return; Error: freeimage(back); freeimage(high); freeimage(bord); back = display->white; high = display->black; bord = display->black; text = display->black; htext = display->white; } /* * r is a rectangle holding the text elements. * return the rectangle, including its black edge, holding element i. */ static Rectangle menurect(Rectangle r, int i) { if(i < 0) return Rect(0, 0, 0, 0); r.min.y += (font->height+Vspacing)*i; r.max.y = r.min.y+font->height+Vspacing; return insetrect(r, Border-Margin); } /* * r is a rectangle holding the text elements. * return the element number containing p. */ static int menusel(Rectangle r, Point p) { if(!ptinrect(p, r)) return -1; return (p.y-r.min.y)/(font->height+Vspacing); } static void paintitem(Menu *menu, Rectangle textr, int off, int i, int highlight, Image *save, Image *restore) { char *item; Rectangle r; Point pt; if(i < 0) return; r = menurect(textr, i); if(restore){ draw(screen, r, restore, nil, restore->r.min); return; } if(save) draw(save, save->r, screen, nil, r.min); item = menu->item? menu->item[i+off] : (*menu->gen)(i+off); pt.x = (textr.min.x+textr.max.x-stringwidth(font, item))/2; pt.y = textr.min.y+i*(font->height+Vspacing); draw(screen, r, highlight? high : back, nil, pt); string(screen, pt, highlight? htext : text, pt, font, item); } /* * menur is a rectangle holding all the highlightable text elements. * track mouse while inside the box, return what's selected when button * is raised, -1 as soon as it leaves box. * invariant: nothing is highlighted on entry or exit. */ static int menuscan(Menu *menu, int but, Mouse *m, Rectangle textr, int off, int lasti, Image *save) { int i; paintitem(menu, textr, off, lasti, 1, save, nil); flushimage(display, 1); /* in case display->locking is set */ *m = emouse(); while(m->buttons & (1<<(but-1))){ flushimage(display, 1); /* in case display->locking is set */ *m = emouse(); i = menusel(textr, m->xy); if(i != -1 && i == lasti) continue; paintitem(menu, textr, off, lasti, 0, nil, save); if(i == -1) return i; lasti = i; paintitem(menu, textr, off, lasti, 1, save, nil); } return lasti; } static void menupaint(Menu *menu, Rectangle textr, int off, int nitemdrawn) { int i; draw(screen, insetrect(textr, Border-Margin), back, nil, ZP); for(i = 0; i<nitemdrawn; i++) paintitem(menu, textr, off, i, 0, nil, nil); } static void menuscrollpaint(Rectangle scrollr, int off, int nitem, int nitemdrawn) { Rectangle r; draw(screen, scrollr, back, nil, ZP); r.min.x = scrollr.min.x; r.max.x = scrollr.max.x; r.min.y = scrollr.min.y + (Dy(scrollr)*off)/nitem; r.max.y = scrollr.min.y + (Dy(scrollr)*(off+nitemdrawn))/nitem; if(r.max.y < r.min.y+2) r.max.y = r.min.y+2; border(screen, r, 1, bord, ZP); if(menutxt == 0) menutxt = allocimage(display, Rect(0, 0, 1, 1), CMAP8, 1, DDarkgreen); if(menutxt) draw(screen, insetrect(r, 1), menutxt, nil, ZP); } int emenuhit(int but, Mouse *m, Menu *menu) { int i, nitem, nitemdrawn, maxwid, lasti, off, noff, wid, screenitem; int scrolling; Rectangle r, menur, sc, textr, scrollr; Image *b, *save; Point pt; char *item; if(back == nil) menucolors(); sc = screen->clipr; replclipr(screen, 0, screen->r); maxwid = 0; for(nitem = 0; item = menu->item? menu->item[nitem] : (*menu->gen)(nitem); nitem++){ i = stringwidth(font, item); if(i > maxwid) maxwid = i; } if(menu->lasthit<0 || menu->lasthit>=nitem) menu->lasthit = 0; screenitem = (Dy(screen->r)-10)/(font->height+Vspacing); if(nitem>Maxunscroll || nitem>screenitem){ scrolling = 1; nitemdrawn = Nscroll; if(nitemdrawn > screenitem) nitemdrawn = screenitem; wid = maxwid + Gap + Scrollwid; off = menu->lasthit - nitemdrawn/2; if(off < 0) off = 0; if(off > nitem-nitemdrawn) off = nitem-nitemdrawn; lasti = menu->lasthit-off; }else{ scrolling = 0; nitemdrawn = nitem; wid = maxwid; off = 0; lasti = menu->lasthit; } r = insetrect(Rect(0, 0, wid, nitemdrawn*(font->height+Vspacing)), -Margin); r = rectsubpt(r, Pt(wid/2, lasti*(font->height+Vspacing)+font->height/2)); r = rectaddpt(r, m->xy); pt = ZP; if(r.max.x>screen->r.max.x) pt.x = screen->r.max.x-r.max.x; if(r.max.y>screen->r.max.y) pt.y = screen->r.max.y-r.max.y; if(r.min.x<screen->r.min.x) pt.x = screen->r.min.x-r.min.x; if(r.min.y<screen->r.min.y) pt.y = screen->r.min.y-r.min.y; menur = rectaddpt(r, pt); textr.max.x = menur.max.x-Margin; textr.min.x = textr.max.x-maxwid; textr.min.y = menur.min.y+Margin; textr.max.y = textr.min.y + nitemdrawn*(font->height+Vspacing); if(scrolling){ scrollr = insetrect(menur, Border); scrollr.max.x = scrollr.min.x+Scrollwid; }else scrollr = Rect(0, 0, 0, 0); b = allocimage(display, menur, screen->chan, 0, 0); if(b == 0) b = screen; draw(b, menur, screen, nil, menur.min); draw(screen, menur, back, nil, ZP); border(screen, menur, Blackborder, bord, ZP); save = allocimage(display, menurect(textr, 0), screen->chan, 0, -1); r = menurect(textr, lasti); if(pt.x || pt.y) emoveto(divpt(addpt(r.min, r.max), 2)); menupaint(menu, textr, off, nitemdrawn); if(scrolling) menuscrollpaint(scrollr, off, nitem, nitemdrawn); while(m->buttons & (1<<(but-1))){ lasti = menuscan(menu, but, m, textr, off, lasti, save); if(lasti >= 0) break; while(!ptinrect(m->xy, textr) && (m->buttons & (1<<(but-1)))){ if(scrolling && ptinrect(m->xy, scrollr)){ noff = ((m->xy.y-scrollr.min.y)*nitem)/Dy(scrollr); noff -= nitemdrawn/2; if(noff < 0) noff = 0; if(noff > nitem-nitemdrawn) noff = nitem-nitemdrawn; if(noff != off){ off = noff; menupaint(menu, textr, off, nitemdrawn); menuscrollpaint(scrollr, off, nitem, nitemdrawn); } } flushimage(display, 1); /* in case display->locking is set */ *m = emouse(); } } draw(screen, menur, b, nil, menur.min); if(b != screen) freeimage(b); freeimage(save); replclipr(screen, 0, sc); if(lasti >= 0){ menu->lasthit = lasti+off; return menu->lasthit; } return -1; }