How to Use Q1 Buttons in Applications
Keyboard Description
Key | Value | Description |
---|---|---|
Period | KeyEvent.KEYCODE_PERIOD | Black dot button on the right-bottom of the keyboard |
QRCode | 232 | Orange button on the middle-bottom of the keyboard |
Back | KeyEvent.KEYCODE_ESCAPE | Red 'X' button on the left-bottom of the keyboard |
Scan | 229 | Orange button on the left of the LCD |
Delete | KeyEvent.KEYCODE_DEL | Yellow triangle button on the right-top of the keyboard |
Enter | KeyEvent.KEYCODE_ENTER | Green circle button on the right-bottom of the keyboard |
Digital Buttons: Other buttons are standard digital buttons as defined in android.view.KeyEvent.
Scan Button and QR Code Button Usage
- Function: These buttons quickly launch scan applications.
- Process:
- Pressing either button prompts the system to search for installed applications with a scan intent-filter.
- If multiple applications are available, the system displays a list for user selection.
- The selected application will start. The code for the scan intent-filter is as follows:
<action android:name="android.intent.action.SCAN" /> <category android:name="android.intent.category.DEFAULT" />
- Note: If no application with the scan intent-filter is installed, pressing these buttons has no effect.
Implementation in Applications
1. Defining Intent-Filter:
- To use the scan button and the QR code button, your application must define a scan intent-filter in the Android manifest file.
- Specify both the category and action.
<activity android:name="com.XX.activity.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.SCAN" /> <category android:name="android.intent.category.DEFAULT" /> </intent-filter> </activity>
2. Handling Button Press:
- When the button is pressed, the active top task receives the key value.
- Implement the logic in the application's 'onKeyDown' function override.
/** Key code constant: left scan key. */
public static final int KEYCODE_SCAN_LEFT = 229;
/** Key code constant: right scan key. */
public static final int KEYCODE_SCAN_RIGHT = 230;
/** Key code constant: qr key. */
public static final int KEYCODE_QR = 232;
public boolean onKeyDown(int keyCode, KeyEvent event) {
// listen the key code
if (keyCode == KEYCODE_SCAN_LEFT|| keyCode ==KEYCODE_SCAN_RIGHT|| keyCode ==KEYCODE_QR) {
//do something, for example:scanner……
return true;
}
return super.onKeyDown(keyCode, event);
}