Simplify the public event and CPU API

Applications now need far less ceremony: hello.c is a 20-line loop that
handles REFRESH, CLOSE and QUIT and draws into the surface's own pixels.

- Fold GEOMETRY, STATE and FOCUS into one WINDOW event carrying size,
  scale and state; unchanged values send nothing.
- Guarantee REFRESH once a window has a size and after every resize,
  never at size zero.
- Merge DROP_HOVER into DROP with over/leave/data actions and give drag
  and drop actions enums.
- Keep event strings valid until the next wait and drop
  yasl_event_release; empty or failed waits report NONE.
- Replace copy-in presentation with a lent pixel buffer:
  yasl_cpu_pixels and yasl_cpu_present.
- Remove yasl_poll_event, yasl_cpu_read_pixels, unused event fields and
  comments that restated names.
- Wayland: resize floating windows in request_size instead of reporting
  it unsupported, and stop marking new GPU surfaces as Vulkan so
  yasl_vulkan_create_surface no longer fails with NATIVE_WINDOW_IN_USE.

Also includes the in-progress public API refactor that was uncommitted
in the tree (removal of the app/loop layer, new surface, GL and Vulkan
entry points).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 122 insertions, 25 deletions

diff --git a/src/platform/wayland/ime.c b/src/platform/wayland/ime.c
index 4a091d8..62e5936 100644
--- a/src/platform/wayland/ime.c
+++ b/src/platform/wayland/ime.c
@@ -1,5 +1,7 @@
 #include "internal.h"
 
+#include <errno.h>
+
 #define IME_TEXT_MAX (256u * 1024)
 
 static void show_preedit(struct wayland_surface *w, char *text, int begin, int end)
@@ -12,7 +14,7 @@ static void show_preedit(struct wayland_surface *w, char *text, int begin, int e
     w->ime_shown_begin = begin;
     w->ime_shown_end = end;
     if (changed) {
-        yasl_surface_notify_composition(&w->base, w->ime_shown,
+        yasl_private_surface_notify_composition(&w->base, w->ime_shown,
                                         w->ime_shown_begin, w->ime_shown_end);
         wayland_surface_schedule_redraw(w);
     }
@@ -24,21 +26,63 @@ void ime_reset(struct wayland_surface *w)
     w->ime_preedit = NULL;
     free(w->ime_commit);
     w->ime_commit = NULL;
+    w->ime_delete_pending = false;
     show_preedit(w, NULL, -1, -1);
 }
 
 void ime_send_caret(struct wayland_surface *w)
 {
+    wayland_surface_update_text_input(w);
+}
+
+bool wayland_surface_update_text_input(struct wayland_surface *w)
+{
+    if (!w || !w->conn) {
+        errno = EINVAL;
+        return false;
+    }
+    if (!w->conn->text_input_mgr) {
+        errno = ENOTSUP;
+        return false;
+    }
     struct seat *seat = w->ime_seat;
-    if (!seat || !seat->text_input)
-        return;
-    uint32_t scale = w->scale_120 ? w->scale_120 : YASL_SCALE_UNIT;
+    if (!seat || !seat->text_input || seat->ime_focus != w)
+        return true;
+    if (!w->base.text_input_active) {
+        if (seat->ime_enabled) {
+            zwp_text_input_v3_disable(seat->text_input);
+            zwp_text_input_v3_commit(seat->text_input);
+            seat->ime_enabled = false;
+        }
+        ime_reset(w);
+        return true;
+    }
+    if (!seat->ime_enabled) {
+        zwp_text_input_v3_enable(seat->text_input);
+        seat->ime_enabled = true;
+    }
+    unsigned purpose = w->base.text_purpose;
+    if (purpose > ZWP_TEXT_INPUT_V3_CONTENT_PURPOSE_TERMINAL)
+        purpose = ZWP_TEXT_INPUT_V3_CONTENT_PURPOSE_NORMAL;
+    zwp_text_input_v3_set_content_type(seat->text_input,
+            ZWP_TEXT_INPUT_V3_CONTENT_HINT_NONE, purpose);
+    const char *surrounding = w->base.text_surrounding ? w->base.text_surrounding : "";
+    size_t length = w->base.text_surrounding ? w->base.text_length : 0;
+    size_t cursor = w->base.text_surrounding ? w->base.text_end : 0;
+    size_t anchor = w->base.text_surrounding ? w->base.text_begin : 0;
+    if (cursor > length) cursor = length;
+    if (anchor > length) anchor = length;
+    if (length <= INT32_MAX && cursor <= INT32_MAX && anchor <= INT32_MAX)
+        zwp_text_input_v3_set_surrounding_text(seat->text_input, surrounding,
+                (int32_t)cursor, (int32_t)anchor);
+    uint32_t scale = w->scale_120 ? w->scale_120 : YASL_PRIVATE_SCALE_UNIT;
     zwp_text_input_v3_set_cursor_rectangle(seat->text_input,
-            yasl_scale_to_logical(w->ime_caret.x, scale),
-            yasl_scale_to_logical(w->ime_caret.y, scale),
-            yasl_scale_to_logical(w->ime_caret.width, scale),
-            yasl_scale_to_logical(w->ime_caret.height, scale));
+            yasl_private_scale_to_logical(w->ime_caret.x, scale),
+            yasl_private_scale_to_logical(w->ime_caret.y, scale),
+            yasl_private_scale_to_logical(w->ime_caret.width, scale),
+            yasl_private_scale_to_logical(w->ime_caret.height, scale));
     zwp_text_input_v3_commit(seat->text_input);
+    return true;
 }
 
 bool wayland_surface_ime_preedit_cursor(const struct wayland_surface *w, int *begin, int *end)
@@ -50,7 +94,7 @@ bool wayland_surface_ime_preedit_cursor(const struct wayland_surface *w, int *be
     return true;
 }
 
-void wayland_surface_set_ime_caret(struct wayland_surface *w, struct yasl_rect2i caret)
+void wayland_surface_set_ime_caret(struct wayland_surface *w, struct yasl_private_rect2i caret)
 {
     if (!w || (w->ime_caret.x == caret.x && w->ime_caret.y == caret.y &&
                w->ime_caret.width == caret.width && w->ime_caret.height == caret.height))
@@ -62,17 +106,14 @@ void wayland_surface_set_ime_caret(struct wayland_surface *w, struct yasl_rect2i
 static void text_input_enter(void *data, struct zwp_text_input_v3 *text_input,
                              struct wl_surface *surface)
 {
+    (void)text_input;
     struct seat *s = data;
     struct wayland_surface *w = surface_root(surface ?
         (struct wayland_surface *)wl_surface_get_user_data(surface) : NULL);
     s->ime_focus = w;
     if (!w) return;
-    zwp_text_input_v3_enable(text_input);
-    zwp_text_input_v3_set_content_type(text_input,
-            ZWP_TEXT_INPUT_V3_CONTENT_HINT_NONE,
-            ZWP_TEXT_INPUT_V3_CONTENT_PURPOSE_TERMINAL);
     w->ime_seat = s;
-    ime_send_caret(w);
+    wayland_surface_update_text_input(w);
 }
 
 static void text_input_leave(void *data, struct zwp_text_input_v3 *text_input,
@@ -83,8 +124,11 @@ static void text_input_leave(void *data, struct zwp_text_input_v3 *text_input,
     struct wayland_surface *w = s->ime_focus;
     s->ime_focus = NULL;
     if (!w) return;
-    zwp_text_input_v3_disable(text_input);
-    zwp_text_input_v3_commit(text_input);
+    if (s->ime_enabled) {
+        zwp_text_input_v3_disable(text_input);
+        zwp_text_input_v3_commit(text_input);
+        s->ime_enabled = false;
+    }
     if (w->ime_seat == s)
         w->ime_seat = NULL;
     ime_reset(w);
@@ -110,7 +154,7 @@ static void text_input_preedit_string(void *data,
 {
     (void)text_input;
     struct wayland_surface *w = ((struct seat *)data)->ime_focus;
-    if (!w) return;
+    if (!w || !w->base.text_input_active) return;
     keyboard_text_reset((struct seat *)data);
     free(w->ime_preedit);
     w->ime_preedit = text ? copy_text(text) : NULL;
@@ -126,7 +170,7 @@ static void text_input_commit_string(void *data,
 {
     (void)text_input;
     struct wayland_surface *w = ((struct seat *)data)->ime_focus;
-    if (!w) return;
+    if (!w || !w->base.text_input_active) return;
     keyboard_text_reset((struct seat *)data);
     free(w->ime_commit);
     w->ime_commit = (text && text[0]) ? copy_text(text) : NULL;
@@ -136,7 +180,31 @@ static void text_input_delete_surrounding_text(void *data,
         struct zwp_text_input_v3 *text_input, uint32_t before_length,
         uint32_t after_length)
 {
-    (void)data; (void)text_input; (void)before_length; (void)after_length;
+    (void)text_input;
+    struct seat *seat = data;
+    struct wayland_surface *w = seat->ime_focus;
+    if (!w || !w->base.text_input_active || !w->base.text_surrounding)
+        return;
+    size_t length = w->base.text_length;
+    size_t cursor = w->base.text_end <= length ? w->base.text_end : length;
+    while (cursor && cursor < length &&
+           (((unsigned char)w->base.text_surrounding[cursor] & 0xc0) == 0x80))
+        cursor--;
+    size_t begin = before_length > cursor ? 0 : cursor - before_length;
+    size_t end = after_length > length - cursor ? length : cursor + after_length;
+    while (begin && begin < length &&
+           (((unsigned char)w->base.text_surrounding[begin] & 0xc0) == 0x80))
+        begin--;
+    while (end < length && (((unsigned char)w->base.text_surrounding[end] & 0xc0) == 0x80))
+        end++;
+    /* text_input_v3 batches deletion and commit into one `done` group. Keep
+     * the replacement range paired with that group's committed text and
+     * enqueue both together below, preserving snapshot metadata. */
+    w->ime_delete_pending = true;
+    w->ime_delete_begin = begin;
+    w->ime_delete_end = end;
+    w->ime_delete_revision = w->base.text_revision;
+    w->ime_delete_generation = w->base.text_generation;
 }
 
 static void text_input_done(void *data, struct zwp_text_input_v3 *text_input,
@@ -144,17 +212,46 @@ static void text_input_done(void *data, struct zwp_text_input_v3 *text_input,
 {
     (void)text_input; (void)serial;
     struct wayland_surface *w = ((struct seat *)data)->ime_focus;
-    if (!w) return;
-    if (w->ime_commit) {
-        struct yasl_event ev = {
-            .type = YASL_EVENT_TEXT,
+    if (!w || !w->base.text_input_active) return;
+    bool has_snapshot = w->base.text_surrounding != NULL &&
+                        w->base.text_length <= INT32_MAX;
+    bool has_commit = w->ime_commit && w->ime_commit[0];
+    bool edit = w->ime_delete_pending || (has_commit && has_snapshot);
+    if (edit) {
+        size_t begin = w->ime_delete_pending ? w->ime_delete_begin : w->base.text_begin;
+        size_t end = w->ime_delete_pending ? w->ime_delete_end : w->base.text_end;
+        if (begin > w->base.text_length) begin = w->base.text_length;
+        if (end > w->base.text_length) end = w->base.text_length;
+        if (end < begin) end = begin;
+        struct yasl_private_event ev = {
+            .type = YASL_PRIVATE_EVENT_TEXT_EDIT,
+            .surface = &w->base,
+            .text_edit = {
+                .data = has_commit ? w->ime_commit : "",
+                .len = has_commit ? strlen(w->ime_commit) : 0,
+                .revision = w->ime_delete_revision,
+                .generation = w->ime_delete_generation,
+                .begin = begin,
+                .end = end,
+            },
+        };
+        if (!w->ime_delete_pending) {
+            ev.text_edit.revision = w->base.text_revision;
+            ev.text_edit.generation = w->base.text_generation;
+        }
+        input_queue_push(&w->input, &ev);
+        w->ime_delete_pending = false;
+    }
+    if (w->ime_commit && !edit) {
+        struct yasl_private_event ev = {
+            .type = YASL_PRIVATE_EVENT_TEXT,
             .surface = &w->base,
             .text = { .data = w->ime_commit, .len = strlen(w->ime_commit) },
         };
         input_queue_push(&w->input, &ev);
-        free(w->ime_commit);
-        w->ime_commit = NULL;
     }
+    free(w->ime_commit);
+    w->ime_commit = NULL;
     char *preedit = w->ime_preedit && w->ime_preedit[0] ? w->ime_preedit : NULL;
     if (!preedit)
         free(w->ime_preedit);