Import of the watch repository from Pebble

src/fw/applib/ui/window_stack_private.h

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+/*
+ * 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.
+ */
+
+//! Private API for manipulating the Window Stack
+#pragma once
+
+#include "window.h"
+#include "window_stack_animation.h"
+#include "util/list.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#define WINDOW_STACK_ITEMS_MAX (16)
+
+//! @internal
+//! Data structure for an item on a window stack
+typedef struct WindowStackItem {
+  ListNode list_node;
+  Window *window;
+  const WindowTransitionImplementation *pop_transition_implementation;
+} WindowStackItem;
+
+//! @internal
+//! Data structure for a stack of windows
+typedef struct WindowStack {
+  //! The item that is on top of the stack, after the last time changes were processed.
+  WindowStackItem *last_top_item;
+
+  //! The actual stack of windows. The first item in this list is the top item.
+  ListNode *list_head;
+
+  //! The list of window items that have been removed and need to be unloaded.
+  ListNode *removed_list_head;
+
+  //! Lock pushing to the stack. If this is true, pushing will not occur.
+  bool lock_push;
+
+  //! The TransitioningContext object stores the current transition being done on
+  //! the window stack provided that an animation has been scheduled.
+  WindowTransitioningContext transition_context;
+} WindowStack;
+
+//! Legacy handler for window transitioning.
+//! @param stack The \ref WindowStack of the transitioning window.
+//! @param window The \ref Window transitioning in.
+bool window_transition_context_has_legacy_window_to(WindowStack *stack, Window *window);
+
+//! Transitioning function called when the current visible window disappears.
+//! If there is no window_to pointer (it is NULL), then this is a no-op.
+//! @param context The \ref WindowTransitionContext of the transitioning window
+void window_transition_context_disappear(WindowTransitioningContext *context);
+
+//! Transitioning function called when the new window, window_to in the context, appears on
+//! the screen.  If there is no window_to pointer (it is NULL), then this is a no-op.
+//! @param context The \ref WindowTransitionContext of the transitioning window
+void window_transition_context_appear(WindowTransitioningContext *context);
+
+//! @internal
+//! A member of a window stack dump array
+typedef struct WindowStackDump {
+  Window *addr;
+  const char *name;
+} WindowStackDump;
+
+//! @internal
+//! Walk and copy the window stack to an array for debug purposes.
+//! @param stack The \ref WindowStack to dump.
+//! @param[out] dump The windows in the stack, top of stack first.
+//! @return Number of windows in the stack dump.
+//!
+//! The window stack dump array is allocated on the kernel heap.
+//! It is the caller's responsibility to free the array.
+//!
+//! @note If the function is unable to allocate the dump array, *dump
+//! will be set to NULL but the function will still return the depth
+//! of the window stack.
+size_t window_stack_dump(WindowStack *stack, WindowStackDump **dump);