From d8601f23f522ed552055bf5a3f6905fe0342fce1 Mon Sep 17 00:00:00 2001
From: hippoz <10706925-hippoz@users.noreply.gitlab.com>
Date: Tue, 25 Apr 2023 14:39:37 +0300
Subject: [PATCH] improve text input and add caret

---
 src/box-layout-node.c |  2 +-
 src/node.c            | 42 +++++++++++++++++++++++++++++------------
 src/node.h            |  2 ++
 src/text-input-node.c | 44 +++++++++++++++++++++++++++++++++++++------
 src/text-input-node.h |  1 +
 src/text-node.c       | 26 +++++++++++++++++++++++++
 src/text-node.h       |  2 ++
 7 files changed, 100 insertions(+), 19 deletions(-)

diff --git a/src/box-layout-node.c b/src/box-layout-node.c
index 6086cc2..220e93d 100644
--- a/src/box-layout-node.c
+++ b/src/box-layout-node.c
@@ -140,7 +140,7 @@ int box_layout_handle(UINode *component, enum UIEvent ev, size_t d, void *p)
 
             current_index++;
         }
-        return 1;
+        return 0;
     }
     return 0;
 }
diff --git a/src/node.c b/src/node.c
index 206e8ec..4f0971b 100644
--- a/src/node.c
+++ b/src/node.c
@@ -6,8 +6,28 @@
 typedef struct UIWindow UIWindow;
 int window_invalidate_node(UIWindow *window, UINode *node);
 
+int node_send(UINode *node, enum UIEvent ev, size_t d, void *p)
+{
+    if (node->flags & UI_NODE_DISABLED) {
+        return 0;
+    }
+
+    if (node->handle) {
+        int result = (node->handle)(node, ev, d, p);
+        if (result) return result;
+    }
+    if (node->handle_proto) {
+        return (node->handle_proto)(node, ev, d, p);
+    }
+    return 0;
+}
+
 int node_dispatch(UINode *node, enum UIEvent ev, size_t d, void *p)
 {
+    if (node->flags & UI_NODE_DISABLED) {
+        return 0;
+    }
+
     for (int i = 0; i < node->nodes_count; i++) {
         if (node->nodes[i]->flags & UI_NODE_COMPONENT) {
             int result = node_dispatch(node->nodes[i], ev, d, p);
@@ -27,10 +47,11 @@ int node_dispatch(UINode *node, enum UIEvent ev, size_t d, void *p)
 UINode *node_by_point(UINode *root, double x, double y)
 {
     for (int i = 0; i < root->nodes_count; i++) {
-        double local_x = x - root->nodes[i]->window_rel_x;
-        double local_y = y - root->nodes[i]->window_rel_y;
-        if (ui_rect_contains_point(&root->nodes[i]->rect, local_x, local_y)) {
-            return node_by_point(root->nodes[i], local_x, local_y);
+        UINode *node = root->nodes[i];
+        double local_x = x - node->window_rel_x;
+        double local_y = y - node->window_rel_y;
+        if (ui_rect_contains_point(&node->rect, local_x, local_y) && !(node->flags & UI_NODE_DISABLED)) {
+            return node_by_point(node, local_x, local_y);
         }
     }
     return root;
@@ -72,7 +93,7 @@ void node_repaint(UINode *node, UIRect *rect, bool do_group, double window_rel_x
     node->window_rel_x = window_rel_x;
     node->window_rel_y = window_rel_y;
 
-    if (!ui_rect_overlap_rect(rect, &node->rect)) {
+    if (!ui_rect_overlap_rect(rect, &node->rect) && !(node->flags & UI_NODE_COMPONENT)) {
         return;
     }
 
@@ -85,18 +106,15 @@ void node_repaint(UINode *node, UIRect *rect, bool do_group, double window_rel_x
 
     cairo_translate(node->drw, node->rect.x, node->rect.y);
 
-    node_dispatch(node, UI_EVENT_REPAINT, 0, NULL);
+    node_send(node, UI_EVENT_REPAINT, 0, 0);
 
     UIRect local_rect = { rect->x - node->rect.x, rect->y - node->rect.y, rect->w, rect->h };
     for (int i = 0; i < node->nodes_count; i++) {
         UINode *current = node->nodes[i];
-        if (current->flags & UI_NODE_COMPONENT) {
-            cairo_save(current->drw);
-            node_dispatch(current, UI_EVENT_REPAINT, 0, NULL);
-            cairo_restore(current->drw);
-        } else {
-            node_repaint(node->nodes[i], &local_rect, false, window_rel_x + node->rect.x, window_rel_y + node->rect.y);
+        if (current->flags & UI_NODE_DISABLED) {
+            continue;
         }
+        node_repaint(current, &local_rect, false, window_rel_x + node->rect.x, window_rel_y + node->rect.y);
     }
 
     cairo_restore(node->drw);
diff --git a/src/node.h b/src/node.h
index a77bc46..dd788fa 100644
--- a/src/node.h
+++ b/src/node.h
@@ -39,6 +39,7 @@ enum UIDirection {
 
 #define UI_NODE_COMPONENT (1 << 0)
 #define UI_NODE_RETAINS_PRESS (1 << 1)
+#define UI_NODE_DISABLED (1 << 2)
 
 typedef struct UINode {
     const char *text;
@@ -57,6 +58,7 @@ typedef struct UINode {
     int (*handle_proto)(struct UINode *node, enum UIEvent ev, size_t d, void *p);
 } UINode;
 
+int node_send(UINode *node, enum UIEvent ev, size_t d, void *p);
 int node_dispatch(UINode *node, enum UIEvent ev, size_t d, void *p);
 UINode *node_by_point(UINode *root, double x, double y);
 void node_init(UINode *node);
diff --git a/src/text-input-node.c b/src/text-input-node.c
index 8d7cc34..0d693ff 100644
--- a/src/text-input-node.c
+++ b/src/text-input-node.c
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <xkbcommon/xkbcommon.h>
+#include <xkbcommon/xkbcommon-keysyms.h>
 #include "node.h"
 #include "text-node.h"
 #include "text-input-node.h"
@@ -14,6 +15,7 @@ UITextInputNode *text_input_new(UINode *parent)
     n->node.handle_proto = text_input_handle;
     n->text = calloc(1, 1);
     n->text_size = 1;
+    n->text_cursor_index = 0;
     node_attach(parent, (UINode*)n);
     return n;
 }
@@ -24,21 +26,51 @@ int text_input_handle(UINode *node, enum UIEvent ev, size_t d, void *p)
 
     switch (ev) {
         case UI_EVENT_KEY_DOWN: {
-            unsigned int keycode = d;
+            xkb_keycode_t keycode = d;
             struct xkb_state *xkb_state = (struct xkb_state*)p;
+            xkb_keysym_t keysym = xkb_state_key_get_one_sym(xkb_state, keycode);
 
-            size_t key_size = xkb_state_key_get_utf8(xkb_state, keycode, NULL, 0) + 1;
-            size_t new_text_size = n->text_size + key_size - 1;
-            n->text = realloc(n->text, new_text_size);
-            xkb_state_key_get_utf8(xkb_state, keycode, n->text + n->text_size - 1, key_size);
-            n->text_size = new_text_size;
+            switch (keysym) {
+                case XKB_KEY_BackSpace: {
+                    if (n->text_cursor_index > 0 && n->text_size > 1) {
+                        n->text[--n->text_cursor_index] = '\0';
+                        n->text = realloc(n->text, n->text_size--);
+                    }
+                    break;
+                }
+                default: {
+                    size_t key_size = xkb_state_key_get_utf8(xkb_state, keycode, NULL, 0);
+                    size_t new_text_size = n->text_size + key_size;
+                    n->text = realloc(n->text, new_text_size);
+                    xkb_state_key_get_utf8(xkb_state, keycode, n->text + n->text_cursor_index, key_size + 1);
+                    n->text_cursor_index += key_size;
+                    n->text_size = new_text_size;                   
+                    break;
+                }
+            }
 
             if (n->text_node) {
                 n->text_node->pending_text = n->text;
+                n->text_node->caret_index = n->text_cursor_index;
                 node_request_relayout(&n->text_node->node);
             }
+
             return 1;
         }
+        case UI_EVENT_PRESSED: {
+            if (n->text_node) {
+                n->text_node->caret_index = n->text_cursor_index;
+                node_request_relayout(&n->text_node->node);
+            }
+            break;
+        }
+        case UI_EVENT_UNPRESSED: {
+            if (n->text_node) {
+                n->text_node->caret_index = -1;
+                node_request_relayout(&n->text_node->node);
+            }
+            break;
+        }
         default: {
             break;
         }
diff --git a/src/text-input-node.h b/src/text-input-node.h
index 4c73d24..05634d6 100644
--- a/src/text-input-node.h
+++ b/src/text-input-node.h
@@ -9,6 +9,7 @@ typedef struct UITextInputNode {
     UITextNode *text_node;
     char *text;
     size_t text_size;
+    size_t text_cursor_index;
 } UITextInputNode;
 
 UITextInputNode *text_input_new(UINode *parent);
diff --git a/src/text-node.c b/src/text-node.c
index bfeacf7..1b7684a 100644
--- a/src/text-node.c
+++ b/src/text-node.c
@@ -1,5 +1,9 @@
 #include <pango/pango.h>
 #include <pango/pangocairo.h>
+#include "background-node.h"
+#include "node.h"
+#include "pango/pango-layout.h"
+#include "pango/pango-types.h"
 #include "text-node.h"
 
 UITextNode *text_node_new(UINode *parent, PangoFontDescription *desc, UIRGBA color, char *text)
@@ -11,6 +15,8 @@ UITextNode *text_node_new(UINode *parent, PangoFontDescription *desc, UIRGBA col
     n->desc = desc;
     n->layout = NULL;
     n->color = color;
+    n->caret_index = -1;
+    n->caret_node = NULL;
     n->node.text = "text";
     n->node.handle_proto = text_node_handle;
     node_attach(parent, (UINode*)n);
@@ -76,6 +82,26 @@ int text_node_handle(UINode *node, enum UIEvent ev, size_t d, void *p)
                 break;
             }
             pango_cairo_update_layout(n->node.drw, n->layout);
+            if (n->caret_index >= 0) {
+                if (!n->caret_node) {
+                    n->caret_node = node_new(&n->node, "caret");
+                    background_node_new(n->caret_node, n->color, 0.0);
+                }
+                PangoRectangle rect;
+                pango_layout_get_cursor_pos(n->layout, n->caret_index, &rect, NULL);
+                n->caret_node->rect = (UIRect){
+                    .x = pango_units_to_double(rect.x),
+                    .y = pango_units_to_double(rect.y),
+                    .w = 1.0,
+                    .h = pango_units_to_double(rect.height),
+                };
+                n->caret_node->flags &= ~UI_NODE_DISABLED;
+                node_dispatch(n->caret_node, UI_EVENT_RELAYOUT, 0, 0);
+            } else {
+                if (n->caret_node) {
+                    n->caret_node->flags |= UI_NODE_DISABLED;
+                }
+            }
             break;
         }
         case UI_EVENT_DESTROY: {
diff --git a/src/text-node.h b/src/text-node.h
index b404693..dc5b9de 100644
--- a/src/text-node.h
+++ b/src/text-node.h
@@ -13,6 +13,8 @@ typedef struct UITextNode {
     PangoLayout *layout;
     char *pending_text;
     UIRGBA color;
+    ssize_t caret_index;
+    UINode *caret_node;
 } UITextNode;
 
 int text_node_handle(UINode *node, enum UIEvent ev, size_t d, void *p);