Badge: Displaying the Notification (Badge) Count on the Home Screen

This tutorial demonstrates how you can create, manage, and remove a badge for an application. A badge is an image displayed on the application icon, which informs the user about notifications and events.

Warm-up

Become familiar with the Badge API basics by learning about:

Initializing the Badge Functionality
Initialize the badge functionality for use.
Creating a Badge
Create a badge for an application.
Managing the Badge
Get and set the count and display attributes for the badge.
Removing the Badge
Remove the badge from the application.

Initializing the Badge Functionality

To initialize badges:

To use the functions and data types of the Badge API (in mobile and wearable applications), include the <badge.h> header file in your application:
```
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <badge.h>
```
The badge functionality requires the http://tizen.org/privilege/notification privilege.
Declare the variables for the return value and application (package name):
```
static int ret = 0;

#define TEST_PKG "org.tizen.badgeapp"
```
To determine if a Badge API function has been correctly executed, check its return value. If the value is different from BADGE_ERROR_NONE, an error has occurred.

Creating a Badge

To create a badge for an application, call the badge_new() function:

badge_new(const char *writable_app_id)

The application calling the badge_new() function has the ownership of the badge. And the writable_app_id parameter means the application which is to be authorized to change the badge.

ret = badge_new(TEST_PKG);
if (ret != BADGE_ERROR_NONE)
{
   // Error handling
}

Managing the Badge

To manage the badge:

Get the count attribute:
The count attribute is displayed in the right corner of the badge and its value must be an integer.

To get the count attribute, call the badge_get_count() function:
```
badge_get_count(const char *app_id, unsigned int *count)
```
The function takes the following parameters:
- [in] app_id: The name of the application that gets the count of the badge.
- [out] count: The value of the count attribute.
```
unsigned int count = 0;
ret = badge_get_count(TEST_PKG, &count);
if (ret != BADGE_ERROR_NONE)
{
   // Error handling
}
```
Set the count attribute:
To set the count attribute, call the badge_set_count() function:
```
badge_set_count(const char *app_id, unsigned int count)
```
The function takes the following parameters:
- [in] app_id: The name of the application that sets the count of the badge.
- [in] count: The new value for the count attribute.
```
ret = badge_set_count(TEST_PKG, count+1);
if (ret != BADGE_ERROR_NONE)
{
   // Error handling
}
```
Getting the display attribute:
You can check whether the badge is visible by getting its display attribute.

The app_id parameter refers to the application which is the owner of the badge.

To get the display attribute, call the badge_get_display() function:
```
badge_get_display(const char *app_id, unsigned int *is_display)
```
The function takes the following parameters:
- [in] app_id: The name of the application that gets the display flag of the badge.
- [out] is_display: The value of the display attribute (1 = badge is visible, 0 = badge is hidden).
```
unsigned int is_displayed = false;
ret = badge_get_display(TEST_PKG, &is_displayed);
if (ret != BADGE_ERROR_NONE)
{
   // Error handling
}
```
Setting the display attribute:
You can display or hide the badge by setting its display attribute accordingly.

To set the display attribute, call the badge_set_display() function:
```
badge_set_display(const char *app_id, unsigned int is_display)
```
The function takes the following parameters:
- [in] app_id: The name of the application that gets the display flag of the badge.
- [in] is_display: The new value for the display attribute (1 = badge is visible, 0 = badge is hidden).
```
ret = badge_set_display(TEST_PKG, 1);
if (ret != BADGE_ERROR_NONE)
{
   // Error handling
}
```

Removing the Badge

To remove the badge from the application, call the badge_remove() function:

badge_remove(const char *app_id)

The function takes the following parameters:

[in] app_id: The ID of the application whose badge to remove.

ret = badge_remove(TEST_PKG);
if (ret != BADGE_ERROR_NONE)
{
   // Error handling
}