I want to display two Activities on one screen at time, and I suppouse the best way is using Fragments.
The problems is I want to do something like that:

Initially, only will display the Activity 1, and when an event success, the Activity 2 will appear (but only the header).
Then, when the users tap on this header, the Activity 2 will go up with some kind of animation. The best aproach should be the posibility to drag the Activity 2 to the top, but initially, it’s enough tapping and go up automatically.
Right now I have the two Activities implemented separately, and I want to merge on one screen.
Thanks.
Your instinct of using Fragments instead of separate Activities for this is a good one. Treat the Activity like a container for these interactions.
Remember that both Activities and Fragments are lifecycle management constructs. They have some conveniences and shortcuts for managing UI, but they aren’t Views themselves. What the user will see and interact with comes down to the Views in your window’s hierarchy.
Have a look at SlidingDrawer as a component that could act as a container for the content of your detail Fragment, the one you’re calling “Activity 2” above. Choosing a list item could turn the SlidingDrawer components visible and populate the drawer with an appropriate detail Fragment’s content.