Modify the default font size of the android System

The font size of the android system is set to "font size" in "display" in "Settings". A total of four levels are provided: small, normal, large, and super large.

Select the corresponding configuration code location for the four levels

Packages/apps/setttings/res/values/arrays. xml

 
 

  
  
<string-array name="entries_font_size">

  
  
<item msgid="6490061470416867723">Small</item>

  
  
<item msgid="3579015730662088893">Normal</item>

  
  
<item msgid="1678068858001018666">Large</item>

  
  
<item msgid="490158884605093126">Huge</item>

  
  
</string-array>

  
  


  
  
<string-array name="entryvalues_font_size" translatable="false">

  
  
<item>0.85</item>

  
  
<item>1.0</item>

  
  
<item>1.15</item>

  
  
<item>1.30</item>

  
  
</string-array>
 
 

The above configuration is provided to the end user after being loaded using the following code
Packages/app/settings/DisplaySettings. java

 
 

  
  
public void readFontSizePreference(ListPreference pref) {

  
  
try {

  
  
mCurConfig.updateFrom(ActivityManagerNative.getDefault().getConfiguration());

  
  
} catch (RemoteException e) {

  
  
Log.w(TAG, "Unable to retrieve font size");

  
  
}

  
  


  
  
// mark the appropriate item in the preferences list

  
  
int index = floatToIndex(mCurConfig.fontScale);

  
  
pref.setValueIndex(index);

  
  


  
  
// report the current size in the summary text

  
  
final Resources res = getResources();

  
  
String[] fontSizeNames = res.getStringArray(R.array.entries_font_size);

  
  
pref.setSummary(String.format(res.getString(R.string.summary_font_size),

  
  
fontSizeNames[index]));

  
  
}
 
 

At the frameworks layer, a default font size is set for the system. The font scale-down ratio is 1, which is the "normal" font in the corresponding display settings.

Frameworks/base/core/java/android/content/res/Configuration. java

 
 

  
  
/**

  
  
* Set this object to the system defaults.

  
  
*/

  
  
Public void setToDefaults (){

  
  
FontScale = 1; // The default font scale is assigned here.
  
  
Mcc = mnc = 0;

  
  
Locale = null;

  
  
UserSetLocale = false;

  
  
Touchscreen = TOUCHSCREEN_UNDEFINED;

  
  
Keyboard = KEYBOARD_UNDEFINED;

  
  
KeyboardHidden = KEYBOARDHIDDEN_UNDEFINED;

  
  
HardKeyboardHidden = HARDKEYBOARDHIDDEN_UNDEFINED;

  
  
Navigation = NAVIGATION_UNDEFINED;

  
  
NavigationHidden = NAVIGATIONHIDDEN_UNDEFINED;

  
  
Orientation = ORIENTATION_UNDEFINED;

  
  
ScreenLayout = SCREENLAYOUT_UNDEFINED;

  
  
UiMode = UI_MODE_TYPE_UNDEFINED;

  
  
ScreenWidthDp = compatScreenWidthDp = SCREEN_WIDTH_DP_UNDEFINED;

  
  
ScreenHeightDp = compatScreenHeightDp = SCREEN_HEIGHT_DP_UNDEFINED;

  
  
SmallestScreenWidthDp = compatSmallestScreenWidthDp = SMALLEST_SCREEN_WIDTH_DP_UNDEFINED;

  
  
DensityDpi = DENSITY_DPI_UNDEFINED;

  
  
Seq = 0;

  
  
}