Electronic device including flexible display

1. An electronic device comprising:

a motor;

a housing configured to be extended or reduced by the motor;

a flexible display configured to change a size of a display region according to extension of the housing or reduction of the housing; and

a processor,

wherein the processor is configured to:

display a multi-window in the display region,

receive a notification in the display region,

receive a user input for extending the display region at a position at which the notification is displayed,

in response to receiving the user input and based on a position of the user input,

extend the display region according to a movement of the housing, and

execute an application related to the notification to be displayed in the extended display region of the display.

2. The electronic device of claim 1 , wherein the processor is further configured to extend the display region according to an extension of the housing.

3. The electronic device of claim 2 , wherein the processor is further configured to display the executed application in a window in the extended display region of the display.

4. The electronic device of claim 3 , wherein, in the window displayed in the extended display region, a pre-extension window is extended and displayed or a hidden region of the pre-extension window is further displayed.

5. The electronic device of claim 2 , wherein the processor is further configured to determine that the position of the user input is a boundary of the multi-window.

6. The electronic device of claim 5 , wherein the processor is further configured to display a predetermined window in the display region.

7. The electronic device of claim 6 , wherein the predetermined window comprises a window in which one of a home screen or a screen having a particular application executed thereon is displayed.

8. The electronic device of claim 1 , wherein the processor is further configured to reduce the display region according to the reduction of housing.

9. The electronic device of claim 8 , wherein the processor is further configured to identify a window corresponding to a position of an other user input in the multi-window.

10. The electronic device of claim 9 , wherein the processor is further configured to display the identified window in a reduced display region.

11. The electronic device of claim 8 , wherein the processor is further configured to determine that the other user input is positioned outside the display region.

12. The electronic device of claim 11 , wherein the processor is further configured to display, in the reduced display region, a multi-window displayed in a pre-extension display region of the display.

13. An operation method of an electronic device, the method comprising:

displaying a multi-window in a display region of a display the display being a flexible display configured to change a size of the display region according to extension of a housing or reduction of the housing, wherein the housing is configured to be extended or reduced by a motor;

displaying a notification in the display region;

receiving a user input for extending the display region at a position at which the notification is displayed;

in response to receiving the user input and based on a position of the user input,

extending the display region according to a movement of the housing; and

executing an application related to the notification to be displayed in the extended display region of the display.

14. The operation method of claim 13 , wherein the extending the display region comprises extending the display region according to an extension of the housing.

15. The operation method of claim 14 , further comprising:

displaying the executed application in a window in the extended display region of the display.

16. The operation method of claim 15 , further comprising:

displaying a pre-extension window in the extended display region of the display or further displaying a hidden region of the pre-extension window in the extended display region of the display.

17. The operation method of claim 14 , further comprising:

selecting a window based on a position of a user input being a boundary of the multi-window.

18. The operation method of claim 17 , further comprising:

displaying a predetermined window in the display region based on the position of the user input being a boundary of the multi-window.