search: wip: re-direct input while searching, and build a search buffer

This adds a new state, 'is_searching'. While active, input is
re-directed, and stored in a search buffer. In the future, we'll use
this buffer and search for its content in the scrollback buffer, and
move the view and create a selection on matches.

When rendering in 'is_searching', everything is dimmed. In the future,
we'll render the current search buffer on-top of the dimmed "regular"
terminal output.

input.c

@@ -18,11 +18,12 @@
 #define LOG_MODULE "input"
 #define LOG_ENABLE_DBG 0
 #include "log.h"
-#include "terminal.h"
-#include "render.h"
-#include "keymap.h"
 #include "commands.h"
+#include "keymap.h"
+#include "render.h"
+#include "search.h"
 #include "selection.h"
+#include "terminal.h"
 #include "vt.h"
 
 static void
@@ -178,6 +179,12 @@ keyboard_key(void *data, struct wl_keyboard *wl_keyboard, uint32_t serial,
     xkb_mod_mask_t significant = ctrl | alt | shift | meta;
     xkb_mod_mask_t effective_mods = mods & ~consumed & significant;
 
+    if (term->is_searching) {
+        start_repeater(term, key - 8);
+        search_input(term, key, sym, effective_mods);
+        return;
+    }
+
 #if 0
     for (size_t i = 0; i < 32; i++) {
         if (mods & (1 << i)) {
@@ -220,6 +227,11 @@ keyboard_key(void *data, struct wl_keyboard *wl_keyboard, uint32_t serial,
             selection_from_clipboard(term, serial);
             found_map = true;
         }
+
+        else if (sym == XKB_KEY_R) {
+            search_begin(term);
+            found_map = true;
+        }
     }
 
     for (size_t i = 0; i < sizeof(key_map) / sizeof(key_map[0]) && !found_map; i++) {

meson.build

@@ -90,6 +90,7 @@ executable(
   'main.c',
   'osc.c', 'osc.h',
   'render.c', 'render.h',
+  'search.c', 'search.h',
   'selection.c', 'selection.h',
   'shm.c', 'shm.h',
   'slave.c', 'slave.h',

render.c

@@ -204,6 +204,11 @@ render_cell(struct terminal *term, pixman_image_t *pix,
         bg = color_hex_to_pixman(term->cursor_color.cursor);
     }
 
+    if (term->is_searching) {
+        pixman_color_dim(&fg);
+        pixman_color_dim(&bg);
+    }
+
     struct font *font = attrs_to_font(term, &cell->attrs);
     const struct glyph *glyph = font_glyph_for_wc(font, cell->wc);
 
@@ -216,9 +221,13 @@ render_cell(struct terminal *term, pixman_image_t *pix,
 
     /* Non-block cursors */
     if (has_cursor && !block_cursor) {
-        pixman_color_t cursor_color = term->cursor_color.text >> 31
-            ? color_hex_to_pixman(term->cursor_color.cursor)
-            : fg;
+        pixman_color_t cursor_color;
+        if (term->cursor_color.text >> 31) {
+            cursor_color = color_hex_to_pixman(term->cursor_color.cursor);
+            if (term->is_searching)
+                pixman_color_dim(&cursor_color);
+        } else
+            cursor_color = fg;
 
         if (term->cursor_style == CURSOR_BAR)
             draw_bar(term, pix, &cursor_color, x, y);
@@ -435,9 +444,10 @@ grid_render(struct terminal *term)
         term_damage_view(term);
 
     /* If we resized the window, or is flashing, or just stopped flashing */
-    if (term->render.last_buf != buf || term->flash.active || term->render.was_flashing) {
-        LOG_DBG("new buffer");
-
+    if (term->render.last_buf != buf ||
+        term->flash.active || term->render.was_flashing ||
+        term->is_searching != term->render.was_searching)
+    {
         /* Fill area outside the cell grid with the default background color */
         int rmargin = term->x_margin + term->cols * term->cell_width;
         int bmargin = term->y_margin + term->rows * term->cell_height;
@@ -445,8 +455,10 @@ grid_render(struct terminal *term)
         int bmargin_height = term->height - bmargin;
 
         uint32_t _bg = !term->reverse ? term->colors.bg : term->colors.fg;
-
         pixman_color_t bg = color_hex_to_pixman_with_alpha(_bg, term->colors.alpha);
+        if (term->is_searching)
+            pixman_color_dim(&bg);
+
         pixman_image_fill_rectangles(
             PIXMAN_OP_SRC, pix, &bg, 4,
             (pixman_rectangle16_t[]){
@@ -469,6 +481,7 @@ grid_render(struct terminal *term)
 
         term->render.last_buf = buf;
         term->render.was_flashing = term->flash.active;
+        term->render.was_searching = term->is_searching;
     }
 
     tll_foreach(term->grid->scroll_damage, it) {
@@ -626,6 +639,7 @@ grid_render(struct terminal *term)
 
     if (term->flash.active) {
         /* Note: alpha is pre-computed in each color component */
+        /* TODO: dim while searching */
         pixman_image_fill_rectangles(
             PIXMAN_OP_OVER, pix,
             &(pixman_color_t){.red=0x7fff, .green=0x7fff, .blue=0, .alpha=0x7fff},

search.c

@@ -0,0 +1,107 @@
+#include "search.h"
+
+#include <wchar.h>
+#include <xkbcommon/xkbcommon-compose.h>
+
+#define LOG_MODULE "search"
+#define LOG_ENABLE_DBG 1
+#include "log.h"
+#include "render.h"
+
+void
+search_begin(struct terminal *term)
+{
+    LOG_DBG("search: begin");
+
+    free(term->search.buf);
+    term->search.buf = NULL;
+    term->search.len = 0;
+    term->search.sz = 0;
+    term->is_searching = true;
+
+    render_refresh(term);
+}
+
+void
+search_cancel(struct terminal *term)
+{
+    LOG_DBG("search: cancel");
+
+    free(term->search.buf);
+    term->search.buf = NULL;
+    term->search.len = 0;
+    term->search.sz = 0;
+    term->is_searching = false;
+
+    render_refresh(term);
+}
+
+void
+search_input(struct terminal *term, uint32_t key, xkb_keysym_t sym, xkb_mod_mask_t mods)
+{
+    LOG_DBG("search: input: sym=%d/0x%x, mods=0x%08x", sym, sym, mods);
+
+    const xkb_mod_mask_t ctrl = 1 << term->kbd.mod_ctrl;
+    //const xkb_mod_mask_t alt = 1 << term->kbd.mod_alt;
+    //const xkb_mod_mask_t shift = 1 << term->kbd.mod_shift;
+    //const xkb_mod_mask_t meta = 1 << term->kbd.mod_meta;
+
+    enum xkb_compose_status compose_status = xkb_compose_state_get_status(
+        term->kbd.xkb_compose_state);
+
+    if ((mods == 0 && sym == XKB_KEY_Escape) || (mods == ctrl && sym == XKB_KEY_g))
+        search_cancel(term);
+
+    else if (mods == 0 && sym == XKB_KEY_BackSpace) {
+        if (term->search.len > 0)
+            term->search.buf[--term->search.len] = L'\0';
+    }
+
+    else {
+        uint8_t buf[64] = {0};
+        int count = 0;
+
+        if (compose_status == XKB_COMPOSE_COMPOSED) {
+            count = xkb_compose_state_get_utf8(
+                term->kbd.xkb_compose_state, (char *)buf, sizeof(buf));
+            xkb_compose_state_reset(term->kbd.xkb_compose_state);
+        } else {
+            count = xkb_state_key_get_utf8(
+                term->kbd.xkb_state, key, (char *)buf, sizeof(buf));
+        }
+
+        const char *src = (const char *)buf;
+        mbstate_t ps = {0};
+        size_t wchars = mbsnrtowcs(NULL, &src, count, 0, &ps);
+
+        if (wchars == -1) {
+            LOG_ERRNO("failed to convert %.*s to wchars", count, buf);
+            return;
+        }
+
+        while (term->search.len + wchars >= term->search.sz) {
+            size_t new_sz = term->search.sz == 0 ? 64 : term->search.sz * 2;
+            wchar_t *new_buf = realloc(term->search.buf, new_sz * sizeof(term->search.buf[0]));
+
+            if (new_buf == NULL) {
+                LOG_ERRNO("failed to resize search buffer");
+                return;
+            }
+
+            term->search.buf = new_buf;
+            term->search.sz = new_sz;
+        }
+
+        assert(term->search.len + wchars < term->search.sz);
+
+        memset(&ps, 0, sizeof(ps));
+        mbsnrtowcs(&term->search.buf[term->search.len], &src, count,
+                   term->search.sz - term->search.len - 1, &ps);
+
+        term->search.len += wchars;
+        term->search.buf[term->search.len] = L'\0';
+    }
+
+    LOG_DBG("search: buffer: %S", term->search.buf);
+    render_refresh(term);
+}

search.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <xkbcommon/xkbcommon.h>
+#include "terminal.h"
+
+void search_begin(struct terminal *term);
+void search_cancel(struct terminal *term);
+void search_input(struct terminal *term, uint32_t key, xkb_keysym_t sym, xkb_mod_mask_t mods);

terminal.h

@@ -331,6 +331,13 @@ struct terminal {
         struct primary primary;
     } selection;
 
+    bool is_searching;
+    struct {
+        wchar_t *buf;
+        size_t len;
+        size_t sz;
+    } search;
+
     struct grid normal;
     struct grid alt;
     struct grid *grid;
@@ -368,6 +375,7 @@ struct terminal {
 
         struct buffer *last_buf;     /* Buffer we rendered to last time */
         bool was_flashing;           /* Flash was active last time we rendered */
+        bool was_searching;
     } render;
 };