projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 1cb6db79 EW |
1 | /* |
| 2 | * Copyright (c) 1989 Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 3dd3a9e5 KB |
5 | * This code is derived from software contributed to Berkeley by |
| 6 | * Edward Wang at The University of California, Berkeley. | |
| 7 | * | |
| 87f529ec | 8 | * %sccs.include.redist.c% |
| 1cb6db79 EW |
9 | */ |
| 10 | ||
| 11 | #ifndef lint | |
| 3dd3a9e5 | 12 | static char sccsid[] = "@(#)xxflush.c 3.6 (Berkeley) %G%"; |
| 1cb6db79 EW |
13 | #endif /* not lint */ |
| 14 | ||
| 15 | #include "ww.h" | |
| 16 | #include "xx.h" | |
| 17 | #include "tt.h" | |
| 18 | ||
| 19 | xxflush(intr) | |
| 20 | register intr; | |
| 21 | { | |
| 22 | register struct xx *xp, *xq; | |
| 23 | ||
| 24 | for (xp = xx_head; xp != 0 && !(intr && wwinterrupt()); xp = xq) { | |
| 25 | switch (xp->cmd) { | |
| 26 | case xc_move: | |
| 27 | if (xp->link == 0) | |
| 28 | (*tt.tt_move)(xp->arg0, xp->arg1); | |
| 29 | break; | |
| 30 | case xc_scroll: | |
| 31 | xxflush_scroll(xp); | |
| 32 | break; | |
| 33 | case xc_inschar: | |
| 1cb6db79 | 34 | (*tt.tt_move)(xp->arg0, xp->arg1); |
| d9375810 EW |
35 | tt.tt_nmodes = xp->arg3; |
| 36 | (*tt.tt_inschar)(xp->arg2); | |
| 37 | break; | |
| 38 | case xc_insspace: | |
| 39 | (*tt.tt_move)(xp->arg0, xp->arg1); | |
| 40 | (*tt.tt_insspace)(xp->arg2); | |
| 1cb6db79 EW |
41 | break; |
| 42 | case xc_delchar: | |
| 1cb6db79 EW |
43 | (*tt.tt_move)(xp->arg0, xp->arg1); |
| 44 | (*tt.tt_delchar)(xp->arg2); | |
| 45 | break; | |
| 46 | case xc_clear: | |
| 47 | (*tt.tt_clear)(); | |
| 48 | break; | |
| 49 | case xc_clreos: | |
| 50 | (*tt.tt_move)(xp->arg0, xp->arg1); | |
| 51 | (*tt.tt_clreos)(); | |
| 52 | break; | |
| 53 | case xc_clreol: | |
| 54 | (*tt.tt_move)(xp->arg0, xp->arg1); | |
| 55 | (*tt.tt_clreol)(); | |
| 56 | break; | |
| 57 | case xc_write: | |
| 58 | (*tt.tt_move)(xp->arg0, xp->arg1); | |
| 59 | tt.tt_nmodes = xp->arg3; | |
| 17f96a0f | 60 | (*tt.tt_write)(xp->buf, xp->arg2); |
| 1cb6db79 EW |
61 | break; |
| 62 | } | |
| 63 | xq = xp->link; | |
| 64 | xxfree(xp); | |
| 65 | } | |
| 66 | if ((xx_head = xp) == 0) { | |
| 67 | xx_tail = 0; | |
| 68 | xxbufp = xxbuf; | |
| 1cb6db79 | 69 | } |
| 17f96a0f | 70 | (*tt.tt_flush)(); |
| 1cb6db79 EW |
71 | } |
| 72 | ||
| 73 | xxflush_scroll(xp) | |
| 74 | register struct xx *xp; | |
| 75 | { | |
| 76 | register struct xx *xq; | |
| 77 | ||
| 78 | top: | |
| 79 | if (xp->arg0 == 0) | |
| 80 | return; | |
| 81 | /* | |
| 82 | * We handle retain (da and db) by putting the burden on scrolling up, | |
| 83 | * which is the less common operation. It must ensure that | |
| 84 | * text is not pushed below the screen, so scrolling down doesn't | |
| 85 | * have to worry about it. | |
| 86 | * | |
| 87 | * Try scrolling region (or scrolling the whole screen) first. | |
| 88 | * Can we assume "sr" doesn't push text below the screen | |
| 89 | * so we don't have to worry about retain below? | |
| 90 | * What about scrolling down with a newline? It probably does | |
| 91 | * push text above (with da). Scrolling up would then have | |
| 92 | * to take care of that. | |
| 93 | * It's easy to be fool proof, but that slows things down. | |
| 94 | * The current solution is to disallow tt_scroll_up if da or db is true | |
| 95 | * but cs (scrolling region) is not. Again, we sacrifice scrolling | |
| 96 | * up in favor of scrolling down. The idea is having scrolling regions | |
| 97 | * probably means we can scroll (even the whole screen) with impunity. | |
| 98 | * This lets us work efficiently on simple terminals (use newline | |
| 99 | * on the bottom to scroll), on any terminal without retain, and | |
| 100 | * on vt100 style scrolling regions (I think). | |
| 101 | */ | |
| 102 | if (xp->arg0 > 0) { | |
| 103 | if ((xq = xp->link) != 0 && xq->cmd == xc_scroll && | |
| 104 | xp->arg2 == xq->arg2 && xq->arg0 < 0) { | |
| 105 | if (xp->arg1 < xq->arg1) { | |
| 106 | if (xp->arg2 - xp->arg0 <= xq->arg1) { | |
| 107 | xq->arg0 = xp->arg0; | |
| 108 | xq->arg1 = xp->arg1; | |
| 109 | xq->arg2 = xp->arg2; | |
| 110 | return; | |
| 111 | } | |
| 112 | xp->arg2 = xq->arg1 + xp->arg0; | |
| 113 | xq->arg0 += xp->arg0; | |
| 114 | xq->arg1 = xp->arg2; | |
| 115 | if (xq->arg0 > 0) | |
| 116 | xq->arg1 -= xq->arg0; | |
| 117 | goto top; | |
| 118 | } else { | |
| 119 | if (xp->arg1 - xq->arg0 >= xp->arg2) | |
| 120 | return; | |
| 121 | xq->arg2 = xp->arg1 - xq->arg0; | |
| 122 | xp->arg0 += xq->arg0; | |
| 123 | xp->arg1 = xq->arg2; | |
| 124 | if (xp->arg0 < 0) | |
| 125 | xp->arg1 += xp->arg0; | |
| 126 | goto top; | |
| 127 | } | |
| 128 | } | |
| 129 | if (xp->arg0 > xp->arg2 - xp->arg1) | |
| 130 | xp->arg0 = xp->arg2 - xp->arg1; | |
| 131 | if (tt.tt_scroll_down) { | |
| 132 | if (tt.tt_scroll_top != xp->arg1 || | |
| 133 | tt.tt_scroll_bot != xp->arg2 - 1) { | |
| 134 | if (tt.tt_setscroll == 0) | |
| 135 | goto down; | |
| 136 | (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1); | |
| 137 | } | |
| 138 | tt.tt_scroll_down(xp->arg0); | |
| 139 | } else { | |
| 140 | down: | |
| 141 | (*tt.tt_move)(xp->arg1, 0); | |
| 142 | (*tt.tt_delline)(xp->arg0); | |
| 143 | if (xp->arg2 < tt.tt_nrow) { | |
| 144 | (*tt.tt_move)(xp->arg2 - xp->arg0, 0); | |
| 145 | (*tt.tt_insline)(xp->arg0); | |
| 146 | } | |
| 147 | } | |
| 148 | } else { | |
| 149 | xp->arg0 = - xp->arg0; | |
| 150 | if (xp->arg0 > xp->arg2 - xp->arg1) | |
| 151 | xp->arg0 = xp->arg2 - xp->arg1; | |
| 152 | if (tt.tt_scroll_up) { | |
| 153 | if (tt.tt_scroll_top != xp->arg1 || | |
| 154 | tt.tt_scroll_bot != xp->arg2 - 1) { | |
| 155 | if (tt.tt_setscroll == 0) | |
| 156 | goto up; | |
| 157 | (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1); | |
| 158 | } | |
| 159 | tt.tt_scroll_up(xp->arg0); | |
| 160 | } else { | |
| 161 | up: | |
| 162 | if (tt.tt_retain || xp->arg2 != tt.tt_nrow) { | |
| 163 | (*tt.tt_move)(xp->arg2 - xp->arg0, 0); | |
| 164 | (*tt.tt_delline)(xp->arg0); | |
| 165 | } | |
| 166 | (*tt.tt_move)(xp->arg1, 0); | |
| 167 | (*tt.tt_insline)(xp->arg0); | |
| 168 | } | |
| 169 | } | |
| 170 | } |