CydiaSubstrate tweak

Introduction#

Learn how to create cydia substrate tweaks for jailbroken iPhones.

Those tweaks will enable you to modify the operating system’s behavior to act the way you would like it to.

Remarks#

Installing Theos

https://github.com/theos/theos/wiki/Installation

Create new tweak using Theos

Use nic to create a new project

Enter this command in your terminal

$THEOS/bin/nic.pl

NIC 2.0 - New Instance Creator
------------------------------
  [1.] iphone/activator_event
  [2.] iphone/application_modern
  [3.] iphone/cydget
  [4.] iphone/flipswitch_switch
  [5.] iphone/framework
  [6.] iphone/ios7_notification_center_widget
  [7.] iphone/library
  [8.] iphone/notification_center_widget
  [9.] iphone/preference_bundle_modern
  [10.] iphone/tool
  [11.] iphone/tweak
  [12.] iphone/xpc_service
Choose a Template (required):

Choose template [11.] iphone/tweak

Fill in the details and you will get the following files created:

-rw-r--r--@  1 gkpln3  staff   214B Jun 12 15:09 Makefile
-rw-r--r--@  1 gkpln3  staff    89B Jun 11 22:58 TorchonFocus.plist
-rw-r--r--   1 gkpln3  staff   2.7K Jun 12 16:10 Tweak.xm
-rw-r--r--   1 gkpln3  staff   224B Jun 11 16:17 control
drwxr-xr-x   3 gkpln3  staff   102B Jun 11 16:18 obj
drwxr-xr-x  16 gkpln3  staff   544B Jun 12 16:12 packages

Override iOS screenshots saving method

open the Tweak.xm file using your favorite code editor.

hook to a certain method from the operating system.

%hook SBScreenShotter
- (void)saveScreenshot:(BOOL)screenshot
{
    %orig;
    NSLog(@"saveScreenshot: is called");
}
%end

Note you can choose wether or not the original function should be called, for example:

%hook SBScreenShotter
- (void)saveScreenshot:(BOOL)screenshot
{
    NSLog(@"saveScreenshot: is called");
}
%end

will override the function without calling the original one, thus casing screenshots not being saved.