82 lines
2.4 KiB
Markdown
82 lines
2.4 KiB
Markdown
```eval_rst
|
||
.. include:: /header.rst
|
||
:github_url: |github_link_base|/others/fragment.md
|
||
```
|
||
|
||
# Fragment
|
||
|
||
Fragment is a concept copied from [Android](https://developer.android.com/guide/fragments).
|
||
|
||
It represents a reusable portion of your app's UI. A fragment defines and manages its own layout, has its own lifecycle,
|
||
and can handle its own events. Like Android's Fragment that must be hosted by an activity or another fragment, Fragment
|
||
in LVGL needs to be hosted by an object, or another fragment. The fragment’s view hierarchy becomes part of, or attaches
|
||
to, the host’s view hierarchy.
|
||
|
||
Such concept also has some similarities
|
||
to [UiViewController on iOS](https://developer.apple.com/documentation/uikit/uiviewcontroller).
|
||
|
||
Fragment Manager is a manager holding references to fragments attached to it, and has an internal stack to achieve
|
||
navigation. You can use fragment manager to build navigation stack, or multi pane application easily.
|
||
|
||
## Usage
|
||
|
||
Enable `LV_USE_FRAGMENT` in `lv_conf.h`.
|
||
|
||
### Create Fragment Class
|
||
|
||
```c
|
||
struct sample_fragment_t {
|
||
/* IMPORTANT: don't miss this part */
|
||
lv_fragment_t base;
|
||
/* States, object references and data fields for this fragment */
|
||
const char *title;
|
||
};
|
||
|
||
const lv_fragment_class_t sample_cls = {
|
||
/* Initialize something needed */
|
||
.constructor_cb = sample_fragment_ctor,
|
||
/* Create view objects */
|
||
.create_obj_cb = sample_fragment_create_obj,
|
||
/* IMPORTANT: size of your fragment struct */
|
||
.instance_size = sizeof(struct sample_fragment_t)
|
||
};
|
||
```
|
||
|
||
### Use `lv_fragment_manager`
|
||
|
||
```c
|
||
/* Create fragment instance, and objects will be added to container */
|
||
lv_fragment_manager_t *manager = lv_fragment_manager_create(container, NULL);
|
||
/* Replace current fragment with instance of sample_cls, and init_argument is user defined pointer */
|
||
lv_fragment_manager_replace(manager, &sample_cls, init_argument);
|
||
```
|
||
|
||
### Fragment Based Navigation
|
||
|
||
```c
|
||
/* Add one instance into manager stack. View object of current fragment will be destroyed,
|
||
* but instances created in class constructor will be kept.
|
||
*/
|
||
lv_fragment_manager_push(manager, &sample_cls, NULL);
|
||
|
||
/* Remove the top most fragment from the stack, and bring back previous one. */
|
||
lv_fragment_manager_pop(manager);
|
||
```
|
||
|
||
## Example
|
||
|
||
```eval_rst
|
||
|
||
.. include:: ../../examples/others/fragment/index.rst
|
||
|
||
```
|
||
|
||
## API
|
||
|
||
```eval_rst
|
||
|
||
.. doxygenfile:: lv_fragment.h
|
||
:project: lvgl
|
||
|
||
```
|