Display apparatus and method for displaying

1. A display apparatus comprising:

a flexible display;

a roller configured to roll or unroll the flexible display;

a motor configured to drive the roller; and

a processor configured to:

control the motor to drive the roller to roll or unroll the flexible display based on a size of a first content when a current screen size is different from a screen size of the first content,

control the flexible display to display an image of the first content on an area which is not rolled of the flexible display,

in response to a selection of a second content being received while the first content is displayed and the size of the first content and a size of the second content being different, control the motor to drive the roller to roll or unroll the flexible display based on the size of the second content, and

control the flexible display to display an image of the second content on an area which is not rolled of the flexible display.

2. The apparatus as claimed in claim 1 , wherein the processor is further configured to:

determine a screen ratio of the first content, and

control the motor such that the flexible display has a screen size corresponding to the determined screen ratio.

3. The apparatus as claimed in claim 1 ,

wherein the flexible display has a display area which is flat and is rollable towards one side, and

wherein the motor is configured to vary a screen size of the flexible display by rolling or unrolling a partial area of the display area.

4. The apparatus as claimed in claim 3 , wherein the motor is further configured to vary a width of the flexible display by rolling or unrolling the display area in a transverse direction of the display apparatus.

5. The apparatus as claimed in claim 1 , wherein the processor is further configured to, in response to a particular event occurring, control the motor and the flexible display to display a user interface (UI) element corresponding to the particular event, at a screen size corresponding to the UI element.

6. The apparatus as claimed in claim 5 ,

wherein the particular event is a command to drive a smart television (TV) function, and

wherein the processor is further configured to:

control a channel list to be displayed at a preset first screen size, and

in response to any one channel from among the displayed channel list being selected, control a content corresponding to the selected channel to be displayed at a second screen size which is larger than the first screen size.

7. The apparatus as claimed in claim 5 ,

wherein the particular event is a reception of a notification message regarding an event or state change that occurred in a device connected to the display apparatus within a home network, and

wherein the processor is further configured to:

control the notification message to be displayed at a predetermined first screen size, and

in response to the notification message being selected, control device information corresponding to the notification message to be displayed at a second screen size which is larger than the first screen size.

8. The apparatus as claimed in claim 1 , wherein the processor is further configured to, while rolling or unrolling the flexible display, change a size of an image corresponding to the first content and control the flexible display to display the image.

9. The apparatus as claimed in claim 1 , wherein the processor is further configured to, while rolling or unrolling the flexible display, fix a size of an image corresponding to the first content and control the flexible display to display the image.

10. The apparatus as claimed in claim 1 , wherein the processor is further configured to, while rolling or unrolling the flexible display, control an image corresponding to the first content not to be displayed.

11. The apparatus as claimed in claim 1 , wherein the processor is further configured to, while rolling or unrolling the flexible display, control the flexible display to display a UI element unrelated to the first content.

12. The apparatus as claimed in claim 1 , further comprising:

a transceiver configured to receive screen size information from an external apparatus,

wherein the processor is further configured to control the motor to roll or unroll the flexible display based on the received screen size information and control the flexible display to display the image at a screen size corresponding to the received screen size information.

13. A displaying method of a display apparatus including a flexible display, the displaying method comprising:

rolling or unrolling, by a roller, the flexible display;

driving, by a motor, the roller;

controlling, by a processor, the motor to drive the roller to roll or unroll the flexible display based on a size of a first content when a current screen size is different from a screen size of the first content;

controlling, by the processor, the flexible display to display an image of the first content on an area which is not rolled of the flexible display;

in response to a selection of a second content being received while the first content is displayed and the size of the first content and a size of the second content being different, controlling, by the processor, the motor to drive the roller to roll or unroll the flexible display based on the size of the second content, and

controlling, by the processor, the flexible display to display an image of the second content on an area which is not rolled of the flexible display.

14. The method as claimed in claim 13 , wherein the rolling or unrolling comprises determining a screen ratio of the first content, and determining a screen size corresponding to the determined screen ratio.

15. The method as claimed in claim 13 , wherein the rolling or unrolling comprises rolling or unrolling a display area, which is flat in a transverse direction, of the display apparatus and changing a width of the flexible display.

16. The method as claimed in claim 13 ,

wherein the rolling or unrolling comprises, in response to a particular event occurring, determining a screen size corresponding to a screen ratio of a user interface (UI) element corresponding to the particular event, and

wherein the displaying comprises displaying the UI element.

17. The method as claimed in claim 13 , wherein the displaying comprises, while rolling or unrolling the flexible display, changing a size of an image corresponding to the first content and displaying the image.

18. The method as claimed in claim 13 , wherein the displaying comprises, while rolling or unrolling the flexible display, fixing a size of an image corresponding to the first content and displaying the image.

19. The method as claimed in claim 13 , further comprising:

detecting a user gesture; and

rolling or unrolling the flexible display based on the detected user gesture.

20. The method as claimed in claim 13 , further comprising:

detecting movement of a remote controller; and

rolling or unrolling the flexible display based on the detected movement.