Introduce minimal API for text keyboard request with text area and cursor support

Author: PavelSharp

src/nuklear.h

@@ -4694,6 +4694,11 @@ struct nk_keyboard {
     struct nk_key keys[NK_KEY_MAX];
     char text[NK_INPUT_MAX];
     int text_len;
+
+    /*Text keyboard request system*/
+    nk_bool text_want; /*When true, text input is actively requested*/
+    struct nk_rect text_area; /*Input area (valid only when text_want == true)*/
+    struct nk_rect text_cursor; /*Cursor position (valid only when text_want == true)*/
 };
 
 struct nk_input {
@@ -4718,6 +4723,10 @@ NK_API nk_bool nk_input_is_mouse_released(const struct nk_input*, enum nk_button
 NK_API nk_bool nk_input_is_key_pressed(const struct nk_input*, enum nk_keys);
 NK_API nk_bool nk_input_is_key_released(const struct nk_input*, enum nk_keys);
 NK_API nk_bool nk_input_is_key_down(const struct nk_input*, enum nk_keys);
+/* This is a utility function that should be called inside a widget
+ * to mark text keyboard for opening.
+ * Returns true only on the first request each frame */
+NK_API nk_bool nk_input_want_text_keyboard(struct nk_input*);
 
 /* ===============================================================
  *

src/nuklear_edit.c

@@ -166,6 +166,9 @@ nk_do_edit(nk_flags *state, struct nk_command_buffer *out,
     char cursor_follow = 0;
     struct nk_rect old_clip;
     struct nk_rect clip;
+    /*Variables for text keyboard(kb) support*/
+    nk_bool kb_text_want = nk_false;
+    struct nk_rect kb_text_cursor = nk_rect(0.0f, 0.0f, 0.0f, 0.0f);
 
     NK_ASSERT(state);
     NK_ASSERT(out);
@@ -251,13 +254,17 @@ nk_do_edit(nk_flags *state, struct nk_command_buffer *out,
                 cursor_follow = nk_true;
             }
         }
-        if (old_mode != edit->mode) {
+        /* If mode changes and text keys are pressed in the same frame,
+         * mode change takes priority (may transition to VIEW mode) */
+        if (old_mode != edit->mode)
             in->keyboard.text_len = 0;
-        }}
+        else if (edit->mode == NK_TEXT_EDIT_MODE_INSERT || edit->mode == NK_TEXT_EDIT_MODE_REPLACE)
+            kb_text_want = nk_input_want_text_keyboard(in);
+        }
 
         /* text input */
         edit->filter = filter;
-        if (in->keyboard.text_len) {
+        if (kb_text_want && in->keyboard.text_len) {
             nk_textedit_text(edit, in->keyboard.text, in->keyboard.text_len);
             cursor_follow = nk_true;
             in->keyboard.text_len = 0;
@@ -618,6 +625,7 @@ nk_do_edit(nk_flags *state, struct nk_command_buffer *out,
                 cursor.x = area.x + cursor_pos.x - edit->scrollbar.x;
                 cursor.y = area.y + cursor_pos.y + row_height/2.0f - cursor.h/2.0f;
                 cursor.y -= edit->scrollbar.y;
+                kb_text_cursor = cursor;
                 nk_fill_rect(out, cursor, 0, cursor_color);
             } else {
                 /* draw cursor inside text */
@@ -637,6 +645,7 @@ nk_do_edit(nk_flags *state, struct nk_command_buffer *out,
                 txt.padding = nk_vec2(0,0);
                 txt.background = cursor_color;;
                 txt.text = cursor_text_color;
+                kb_text_cursor = label;
                 nk_fill_rect(out, label, 0, cursor_color);
                 nk_widget_text(out, label, cursor_ptr, glyph_len, &txt, NK_TEXT_LEFT, font);
             }
@@ -673,6 +682,11 @@ nk_do_edit(nk_flags *state, struct nk_command_buffer *out,
             background_color, text_color, nk_false);
     }
     nk_push_scissor(out, old_clip);}
+    if (kb_text_want) {
+        NK_ASSERT(in);
+        in->keyboard.text_cursor = kb_text_cursor;
+        in->keyboard.text_area = clip;
+    }
     return ret;
 }
 NK_API void

src/nuklear_input.c

@@ -17,6 +17,10 @@ nk_input_begin(struct nk_context *ctx)
     for (i = 0; i < NK_BUTTON_MAX; ++i)
         in->mouse.buttons[i].clicked = 0;
 
+    in->keyboard.text_want = nk_false;
+    in->keyboard.text_area = nk_rect(0.0f, 0.0f, 0.0f, 0.0f);
+    in->keyboard.text_cursor = nk_rect(0.0f, 0.0f, 0.0f, 0.0f);
+
     in->keyboard.text_len = 0;
     in->mouse.scroll_delta = nk_vec2(0,0);
     in->mouse.prev.x = in->mouse.pos.x;
@@ -287,4 +291,12 @@ nk_input_is_key_down(const struct nk_input *i, enum nk_keys key)
     if (k->down) return nk_true;
     return nk_false;
 }
-
+NK_API nk_bool
+nk_input_want_text_keyboard(struct nk_input* i)
+{
+    nk_bool ret;
+    NK_ASSERT(i);
+    ret = !i->keyboard.text_want;
+    i->keyboard.text_want = nk_true;
+    return ret;
+}