Import of the watch repository from Pebble

src/fw/applib/ui/text_layer_flow.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "text_layer_flow.h"
+#include "scroll_layer.h"
+
+static bool prv_is_container_layer(const Layer *layer) {
+  return scroll_layer_is_instance(layer);
+}
+
+Layer *text_layer_find_first_paging_container(const TextLayer *text_layer) {
+  Layer *layer = text_layer->layer.parent;
+  while (layer) {
+    if (prv_is_container_layer(layer)) {
+      return layer;
+    }
+    layer = layer->parent;
+  }
+  return NULL;
+}
+
+bool text_layer_calc_text_flow_paging_values(const TextLayer *text_layer,
+                                             GPoint *content_origin_on_screen,
+                                             GRect *page_rect_on_screen) {
+  if (text_layer == NULL || text_layer->layer.window == NULL || text_layer->layer.parent == NULL) {
+    return false;
+  }
+
+  if (content_origin_on_screen) {
+    *content_origin_on_screen = layer_convert_point_to_screen(&text_layer->layer, GPointZero);
+  }
+
+  if (page_rect_on_screen) {
+    const Layer *container =
+      text_layer_find_first_paging_container(text_layer) ?: &text_layer->layer;
+    layer_get_global_frame(container, page_rect_on_screen);
+    if (container == &text_layer->layer) {
+      page_rect_on_screen->size.h = TEXT_LAYER_FLOW_DEFAULT_PAGING_HEIGHT;
+    }
+  }
+
+  return true;
+}