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copied!<p><a href="http://www.sherif.mobi/2012/11/application-which-always-requires-login.html" rel="nofollow">Here is the solution I came up with.</a></p> <p>Please Download the project at the end of the blog post and test it.</p> <p>Tested on: </p> <ul> <li>Samsung S3 running android 4.0.4</li> <li>Emulator running android 2.3.1</li> </ul> <p><strong>The basic idea</strong>: We will create a RequireLoginActivity which will be extended by all our activities except the LoginActivity.</p> <p>Three cases should be captured when the <em>onResume</em> function is called:</p> <ol> <li>Jumping from one RequireLoginActivity to another RequireLoginActivity using a flavor of startActivity.</li> <li>Jumping from one RequireLoginActivity back to a previous RequireLoginActivity by finishing the current activity.</li> <li>Coming back to a RequireLoginActivity after hiding it (we should here show the login!)</li> </ol> <p>The basic idea of my solution is to have 2 counters: number of Started activities (<strong>startCounter</strong>) and number of Paused activities (<strong>pauseCounter</strong>). Each time an activity starts we will increment <strong>startCounter</strong>. Similarly, when an activity pauses, <strong>pauseCounter</strong> should be incremented. In our <em>onResume</em> function, we will decide whether to go to the Sign in by comparing the 2 counters. We will gotoLogin() if the 2 counters are equal!</p> <p>Let me explain: At any time, case 1 can be captured simply because upon starting new activities, our <strong>startCounter</strong> will always be greater that <strong>pauseCounter</strong> by 1. This is true because we will always have one extra activity started but not paused.</p> <p>Also, case 3 is easily captured, because once you leave our app, say, using the HOME button, we will increment the <strong>pauseCounter</strong> and the 2 counters will become equal. Once the app is resumed, the <em>onResume</em> will decide to <strong><em>gotoLogin</em></strong>().</p> <p>Case 2 is a bit tricky, but simple as well. The trick is by overriding the <em>finish</em>() function and decrementing the <strong>startCounter</strong> once and the <strong>pauseCounter</strong> twice in it. Remember that when finishing the activity, <em>onPause</em> is called and our counters are equal. Now by decrementing <strong>startCounter</strong> once and <strong>pauseCounter</strong> twice, we ultimately returned to the counters' values of the previous activity, and <strong>startCounter</strong> will remain greater the <strong>pauseCounter</strong> by 1 when the previous activity resumes.</p>

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