add proper text editing functionality

src/main.c

@@ -13,6 +13,7 @@
 #include "dispatcher-node.h"
 #include "box-layout-node.h"
 #include "colors.h"
+#include <string.h>
 #include <xcb/randr.h>
 
 typedef struct AppState {
@@ -114,6 +115,8 @@ int app_handle(struct UINode *node, void *data, int event_type, size_t d, void *
                 text_input->node.rect.w = 120;
                 text_input->node.rect.h = 32;
                 text_input->text_node = text_node_new(&text_input->node, state->font, UINeutral50, NULL);
+                text_input->text_node->node.width_policy = UI_SIZE_POLICY_GROW;
+                text_input->text_node->node.height_policy = UI_SIZE_POLICY_GROW;
             }
 
             /* a bunch of buttons */
@@ -130,7 +133,7 @@ int app_handle(struct UINode *node, void *data, int event_type, size_t d, void *
 
                 box_layout_new(buttons, UI_DIRECTION_VERTICAL);
 
-                for (int i = 0; i < 10000; i++) {
+                for (int i = 0; i < 20; i++) {
                     UINode *button = node_new(buttons, "button");
                     state_background_node_new(button, UIPurple600, UIPurple700, UIPurple800, 6.0);
                     text_node_new(button, state->font, UINeutral50, "button");

src/str.c

@@ -0,0 +1,31 @@
+#include "str.h"
+#include <string.h>
+
+int ui_string_insert(UIString *str, const size_t where, const char *d, const size_t dsize)
+{
+    size_t required_capacity = str->size + dsize;
+    if (required_capacity > str->capacity) {
+        str->data = realloc(str->data, required_capacity + 1);
+        str->data[required_capacity] = '\0';
+        str->capacity = required_capacity;
+    }
+
+    memmove(str->data + where + dsize, str->data + where, str->capacity - where - dsize);
+    memcpy(str->data + where, d, dsize);
+    str->size += dsize;
+
+    return 0;
+}
+
+int ui_string_delete(UIString *str, const size_t where, const size_t amount)
+{
+    if (str->data + where + amount > str->data + str->capacity) {
+        return -1;
+    }
+
+    memmove(str->data + where, str->data + where + amount, str->capacity - where - amount);
+    str->size -= amount;
+    str->data[str->size] = '\0';
+
+    return 0;
+}

src/str.h

@@ -0,0 +1,15 @@
+#ifndef _UI__STR_H
+#define _UI__STR_H
+
+#include <stdlib.h>
+
+typedef struct UIString {
+    size_t size;
+    size_t capacity;
+    char *data;
+} UIString;
+
+int ui_string_insert(UIString *str, const size_t where, const char *d, const size_t dsize);
+int ui_string_delete(UIString *str, const size_t where, const size_t amount);
+
+#endif

src/text-input-node.c

@@ -1,9 +1,11 @@
 #include <stdlib.h>
+#include <string.h>
 #include <xkbcommon/xkbcommon.h>
 #include <xkbcommon/xkbcommon-keysyms.h>
 #include "node.h"
 #include "text-node.h"
 #include "text-input-node.h"
+#include "str.h"
 
 UITextInputNode *text_input_new(UINode *parent)
 {
@@ -13,8 +15,7 @@ UITextInputNode *text_input_new(UINode *parent)
     n->node.flags = UI_NODE_RETAINS_PRESS;
     n->node.text = "text_input";
     n->node.handle_proto = text_input_handle;
-    n->text = calloc(1, 1);
+    n->text = (UIString){0};
-    n->text_size = 1;
     n->text_cursor_index = 0;
     node_attach(parent, (UINode*)n);
     return n;
@@ -36,26 +37,59 @@ int text_input_handle(UINode *node, enum UIEvent ev, size_t d, void *p)
 
             switch (keysym) {
                 case XKB_KEY_BackSpace: {
-                    if (n->text_cursor_index > 0 && n->text_size > 1) {
+                    if (n->text_cursor_index > 0) {
-                        n->text[--n->text_cursor_index] = '\0';
+                        ui_string_delete(&n->text, --n->text_cursor_index, 1);
-                        n->text = realloc(n->text, n->text_size--);
+                    }
+                    break;
+                }
+                case XKB_KEY_Delete: {
+                    if (n->text_cursor_index > 0 && n->text_cursor_index + 1 <= n->text.size) {
+                        ui_string_delete(&n->text, n->text_cursor_index + 1, 1);
+                    }
+                    if (n->text_cursor_index > n->text.size) {
+                        n->text_cursor_index = n->text.size - 1;
+                    }
+                    break;
+                }
+                case XKB_KEY_Home: {
+                    n->text_cursor_index = 0;
+                    break;
+                }
+                case XKB_KEY_End: {
+                    n->text_cursor_index = n->text.size;
+                    break;
+                }
+                case XKB_KEY_Left: {
+                    if (n->text_cursor_index > 0) {
+                        n->text_cursor_index--;
+                    }
+                    break;
+                }
+                case XKB_KEY_Right: {
+                    if (n->text_cursor_index < n->text.size) {
+                        n->text_cursor_index++;
                     }
                     break;
                 }
                 default: {
-                    size_t key_size = xkb_state_key_get_utf8(xkb_state, keycode, NULL, 0);
+                    size_t input_size = xkb_state_key_get_utf8(xkb_state, keycode, NULL, 0) + 1;
-                    size_t new_text_size = n->text_size + key_size;
+                    if (input_size <= 1) {
-                    n->text = realloc(n->text, new_text_size);
+                        break;
-                    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;                   
+                    char *input_buf = calloc(1, input_size);
+                    xkb_state_key_get_utf8(xkb_state, keycode, input_buf, input_size);
+                    ui_string_insert(&n->text, n->text_cursor_index, input_buf, input_size - 1);
+                    n->text_cursor_index++;
+                    free(input_buf);
                     break;
                 }
             }
 
             if (n->text_node) {
-                n->text_node->pending_text = n->text;
+                n->text_node->pending_text = n->text.data;
                 n->text_node->caret_index = n->text_cursor_index;
+                n->text_node->wrap = true;
                 node_request_relayout(&n->text_node->node);
             }
 

src/text-input-node.h

@@ -3,12 +3,12 @@
 
 #include "node.h"
 #include "text-node.h"
+#include "str.h"
 
 typedef struct UITextInputNode {
     UINode node;
     UITextNode *text_node;
-    char *text;
+    UIString text;
-    size_t text_size;
     size_t text_cursor_index;
 } UITextInputNode;