[hackers] [st] added support for alternate screen. || Aurélien Aptel

changeset: 113:d7ddead9b850
tag: tip
user: Aurélien Aptel <aurelien.aptel_AT_gmail.com>
date: Mon Aug 30 16:48:18 2010 +0200
files: st.c
description:
added support for alternate screen.

diff -r 495e992cf5ae -r d7ddead9b850 st.c
--- a/st.c Mon Aug 30 15:28:29 2010 +0200
+++ b/st.c Mon Aug 30 16:48:18 2010 +0200
@@ -50,7 +50,7 @@
        CURSOR_SAVE, CURSOR_LOAD };
 enum { CURSOR_DEFAULT = 0, CURSOR_HIDE = 1, CURSOR_WRAPNEXT = 2 };
 enum { GLYPH_SET=1, GLYPH_DIRTY=2 };
-enum { MODE_WRAP=1, MODE_INSERT=2, MODE_APPKEYPAD=4 };
+enum { MODE_WRAP=1, MODE_INSERT=2, MODE_APPKEYPAD=4, MODE_ALTSCREEN=8 };
 enum { ESC_START=1, ESC_CSI=2, ESC_OSC=4, ESC_TITLE=8, ESC_ALTCHARSET=16 };
 enum { SCREEN_UPDATE, SCREEN_REDRAW };
 
@@ -86,7 +86,8 @@
 typedef struct {
         int row; /* nb row */
         int col; /* nb col */
- Line* line; /* screen */
+ Line* line; /* screen */
+ Line* alt; /* alternate screen */
         TCursor c; /* cursor */
         int top; /* top scroll limit */
         int bot; /* bottom scroll limit */
@@ -156,6 +157,7 @@
 static void tsetattr(int*, int);
 static void tsetchar(char);
 static void tsetscroll(int, int);
+static void tswapscreen(void);
 
 static void ttynew(void);
 static void ttyread(void);
@@ -337,13 +339,24 @@
         /* set screen size */
         term.row = row, term.col = col;
         term.line = malloc(term.row * sizeof(Line));
- for(row = 0 ; row < term.row; row++)
+ term.alt = malloc(term.row * sizeof(Line));
+ for(row = 0 ; row < term.row; row++) {
                 term.line[row] = malloc(term.col * sizeof(Glyph));
+ term.alt [row] = malloc(term.col * sizeof(Glyph));
+ }
         /* setup screen */
         treset();
 }
 
 void
+tswapscreen(void) {
+ Line* tmp = term.line;
+ term.line = term.alt;
+ term.alt = tmp;
+ term.mode ^= MODE_ALTSCREEN;
+}
+
+void
 tscrolldown (int n) {
         int i;
         Line temp;
@@ -712,10 +725,21 @@
                         case 25:
                                 term.c.state |= CURSOR_HIDE;
                                 break;
- case 1048: /* XXX: no alt. screen to erase/save */
+ case 1047:
+ if(IS_SET(MODE_ALTSCREEN)) {
+ tclearregion(0, 0, term.col-1, term.row-1);
+ tswapscreen();
+ }
+ break;
+ case 1048:
+ tcursor(CURSOR_LOAD);
+ break;
                         case 1049:
                                 tcursor(CURSOR_LOAD);
- tclearregion(0, 0, term.col-1, term.row-1);
+ if(IS_SET(MODE_ALTSCREEN)) {
+ tclearregion(0, 0, term.col-1, term.row-1);
+ tswapscreen();
+ }
                                 break;
                         default:
                                 goto unknown;
@@ -761,10 +785,21 @@
                         case 25:
                                 term.c.state &= ~CURSOR_HIDE;
                                 break;
- case 1048:
- case 1049: /* XXX: no alt. screen to erase/save */
+ case 1047:
+ if(IS_SET(MODE_ALTSCREEN))
+ tclearregion(0, 0, term.col-1, term.row-1);
+ else
+ tswapscreen();
+ break;
+ case 1048:
                                 tcursor(CURSOR_SAVE);
- tclearregion(0, 0, term.col-1, term.row-1);
+ break;
+ case 1049:
+ tcursor(CURSOR_SAVE);
+ if(IS_SET(MODE_ALTSCREEN))
+ tclearregion(0, 0, term.col-1, term.row-1);
+ else
+ tswapscreen();
                                 break;
                         default: goto unknown;
                         }
@@ -889,19 +924,19 @@
                                 treset();
                                 term.esc = 0;
                                 break;
- case '=': /* DECPAM */
+ case '=': /* DECPAM -- Application keypad */
                                 term.mode |= MODE_APPKEYPAD;
                                 term.esc = 0;
                                 break;
- case '>': /* DECPNM */
+ case '>': /* DECPNM -- Normal keypad */
                                 term.mode &= ~MODE_APPKEYPAD;
                                 term.esc = 0;
                                 break;
- case '7':
+ case '7': /* DECSC -- Save Cursor*/
                                 tcursor(CURSOR_SAVE);
                                 term.esc = 0;
                                 break;
- case '8':
+ case '8': /* DECRC -- Restore Cursor */
                                 tcursor(CURSOR_LOAD);
                                 term.esc = 0;
                                 break;
@@ -961,21 +996,28 @@
                 return;
 
         /* free uneeded rows */
- for(i = row; i < term.row; i++)
+ for(i = row; i < term.row; i++) {
                 free(term.line[i]);
+ free(term.alt[i]);
+ }
 
         /* resize to new height */
         term.line = realloc(term.line, row * sizeof(Line));
+ term.line = realloc(term.alt, row * sizeof(Line));
 
         /* resize each row to new width, zero-pad if needed */
         for(i = 0; i < minrow; i++) {
                 term.line[i] = realloc(term.line[i], col * sizeof(Glyph));
+ term.alt[i] = realloc(term.alt[i], col * sizeof(Glyph));
                 memset(term.line[i] + mincol, 0, (col - mincol) * sizeof(Glyph));
+ memset(term.alt[i] + mincol, 0, (col - mincol) * sizeof(Glyph));
         }
 
         /* allocate any new rows */
- for(/* i == minrow */; i < row; i++)
+ for(/* i == minrow */; i < row; i++) {
                 term.line[i] = calloc(col, sizeof(Glyph));
+ term.alt [i] = calloc(col, sizeof(Glyph));
+ }
         
         /* update terminal size */
         term.col = col, term.row = row;
Received on Mon Aug 30 2010 - 16:48:21 CEST