From d81506c0ceee3304bc6dd61417f363f7fe5f4e0d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <fandabohacek@gmail.com>
Date: Thu, 24 Jun 2021 07:41:48 +0200
Subject: [PATCH] feat: add list container logic

---
 lib-gui/include/gui.h            | 30 +++++++++--
 lib-gui/src/gui_list_container.c | 91 ++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+), 3 deletions(-)
 create mode 100644 lib-gui/src/gui_list_container.c

diff --git a/lib-gui/include/gui.h b/lib-gui/include/gui.h
index 6b8a506e930eb7ca5a0f1f8a097590f328bb3c17..8de699b51ffd9a3ea17b90ce1445354f9d0c1289 100644
--- a/lib-gui/include/gui.h
+++ b/lib-gui/include/gui.h
@@ -39,9 +39,17 @@ typedef enum {
   CONT_ONE,
 } container_type_t;
 
+typedef bool (*render_item)(void *state, uint32_t index, renderer_t *renderer, int16_t beg_x, int16_t beg_y);
+
 typedef struct {
-  // items
-  // scroll
+  void *state;
+  render_item render_item_fn;
+  render_item render_header_fn;
+  uint32_t items_count;
+  uint16_t item_height;
+
+  int16_t scroll_x;
+  int16_t scroll_y;
 } list_container_t;
 
 typedef struct {
@@ -301,6 +309,22 @@ component_t *gui_group_container_add_component(container_t *container,
 void gui_group_container_render(gui_t *gui, container_t *container);
 void gui_group_container_update(gui_t *gui, container_t *container);
 
-// handle commands
+// list_container.c
+container_t gui_list_container_create(void *state, uint32_t items_count,
+                                      uint16_t item_height,
+                                      render_item render_it,
+                                      render_item render_header);
+
+void gui_list_scroll(container_t *container, int16_t x, int16_t y);
+bool gui_list_container_set_state(container_t *container, void *state,
+                                  uint32_t items_count);
+bool gui_list_container_set_item_height(container_t *container,
+                                        uint16_t item_height);
+bool gui_list_container_set_render_function(container_t *container,
+                                            render_item render_it,
+                                            render_item render_header);
+
+void gui_list_container_render(gui_t *gui, container_t *container);
+void gui_list_container_update(gui_t *gui, container_t *container);
 
 #endif // __GUI_H__
diff --git a/lib-gui/src/gui_list_container.c b/lib-gui/src/gui_list_container.c
new file mode 100644
index 0000000000000000000000000000000000000000..48bcde658a44dfd3b89af07dcaca5151426bd2d3
--- /dev/null
+++ b/lib-gui/src/gui_list_container.c
@@ -0,0 +1,91 @@
+#include "gui.h"
+#include "renderer.h"
+
+container_t gui_list_container_create(void *state, uint32_t items_count,
+                                      uint16_t item_height,
+                                      render_item render_it,
+                                      render_item render_header) {
+  list_container_t list = {
+    .item_height = item_height,
+    .items_count = items_count,
+    .state = state,
+    .scroll_x = 0,
+    .scroll_y = 0,
+    .render_header_fn = render_header,
+    .render_item_fn = render_it,
+  };
+
+  container_t container = {
+    .focusable = true,
+    .focused = false,
+    .height = item_height * items_count,
+    .width = 0,
+    .inner.list = list,
+    .x = 0,
+    .y = 0
+  };
+
+  return container;
+}
+
+void gui_list_scroll(container_t *container, int16_t x, int16_t y) {
+  container->inner.list.scroll_x += x;
+  container->inner.list.scroll_y += y;
+}
+
+bool gui_list_container_set_state(container_t *container, void *state,
+                                  uint32_t items_count) {
+  container->inner.list.state = state;
+  container->inner.list.items_count = items_count;
+  return true;
+}
+
+bool gui_list_container_set_item_height(container_t *container,
+                                        uint16_t item_height) {
+  container->inner.list.item_height = item_height;
+  return true;
+}
+
+bool gui_list_container_set_render_function(container_t *container, render_item render_it,
+                                            render_item render_header) {
+  container->inner.list.render_item_fn = render_it;
+  container->inner.list.render_header_fn = render_header;
+  return true;
+}
+
+void gui_list_container_render(gui_t *gui, container_t *container) {
+  renderer_translate(gui->renderer, container->x, container->y);
+  renderer_set_draw_area(gui->renderer, gui->size.x, gui->size.y);
+
+  list_container_t list = container->inner.list;
+  if (list.scroll_x < 0) {
+    list.scroll_x = 0;
+  }
+
+  if (list.scroll_y < 0) {
+    list.scroll_y = 0;
+  }
+  container->inner.list = list;
+
+  uint16_t item_height = list.item_height;
+
+  int32_t first_index = list.scroll_y / item_height;
+  if (first_index < 0) {
+    first_index = 0;
+  }
+  uint32_t items_count = gui->size.y / item_height;
+  uint32_t end_index = first_index + items_count;
+
+  int32_t beg_x = -list.scroll_x;
+  int32_t beg_y = -list.scroll_y + first_index * item_height;
+
+  for (int i = first_index; i < end_index; i++) {
+    int32_t y = beg_y + i * item_height;
+
+    list.render_item_fn(list.state, i, gui->renderer, beg_x, y);
+  }
+}
+
+void gui_list_container_update(gui_t *gui, container_t *container) {
+  // do nothing :)
+}