Methods, devices and computer-readable mediums providing chat service

1. A method of providing a chat service, the method comprising:

sequentially displaying, on a display unit of a first device, a plurality of visual signs according to at least one of transmission and reception times of the plurality of visual signs, the plurality of visual signs being included in a conversation between the first device and a plurality of second devices, and being transmitted between the first device and the plurality of second devices;

receiving an edit mode entry command to enter an edit mode in which the plurality of visual signs are editable;

receiving a visual sign selection command selecting one or more of the plurality of visual signs;

changing a display order of the plurality of visual signs by moving the selected one or more of the plurality of visual signs;

fixing, relative to a screen of the display unit, the moved one or more of the plurality of visual signs to a position such that the fixed one or more of the plurality of visual signs do not move in response to sequential display of additional visual signs; and

transmitting, after the changing, edit information indicating the movement and the fixing of the selected one or more of the plurality of visual signs to only a subset of the plurality of second devices, the subset including only second devices among the plurality of second devices that have transmitted at least one of the selected one or more of the plurality of visual signs.

2. The method of claim 1 , wherein

the display unit is a touch sensitive display unit; and

the receiving the visual sign selection command includes

detecting at least one of (i) a touch input at a position on the display unit corresponding to the one or more of the plurality of visual signs, and (ii) a dragging of the position corresponding to the one or more of the plurality of visual signs while holding the touch input.

3. The method of claim 2 , wherein the selected one or more of the plurality of visual signs are moved to a position at which the touch input on the display unit is completed.

4. The method of claim 1 , further comprising:

displaying the selected one or more of the plurality of visual signs discriminatively from others of the plurality of visual signs based on the received visual sign selection command.

5. The method of claim 1 , further comprising:

displaying the moved one or more of the plurality of visual signs discriminatively from others of the plurality of visual signs.

6. The method of claim 1 , further comprising:

receiving an end command to end the edit mode after the receiving of the visual sign selection command.

7. The method of claim 6 , wherein the changing comprises:

moving the selected one or more of the plurality of visual signs to a position at which a most recently transmitted or received visual sign, from among the plurality of the visual signs, is displayed on the display unit in response to receiving the end command.

8. The method of claim 1 , wherein the changing comprises:

moving the selected one or more of the plurality of visual signs in a first direction; and

moving, from among the plurality of visual signs, those visual signs located between an original position of the moved one or more of the plurality of visual signs and a moved position of the moved one or more of the plurality of visual signs in a second direction opposite to the first direction.

9. The method of claim 1 , further comprising:

changing displayed content of the plurality of visual signs by deleting the selected one or more of the plurality of visual signs.

10. The method of claim 1 , wherein the subset of the plurality of second devices is selected by a user of the first device from among the plurality of second devices.

11. The method of claim 1 , further comprising:

receiving, from one or more of the plurality of second devices, information indicating that the display order of the plurality of visual signs has been changed at the one or more of the plurality of second devices,

wherein the changing includes changing the display order of the plurality of visual signs based on the received information.

12. The method of claim 11 , wherein the changing comprises:

changing the display order of the plurality of visual signs based on the received information when the received information is information received from a second device, which is among the plurality of second devices, and which has been selected by a user of the first device.

13. The method of claim 11 , further comprising:

outputting a notification on the display unit when the display order of the plurality of visual signs is changed based on the received information.

14. The method of claim 1 , further comprising:

resetting the changed display order of the plurality of visual signs, the resetting including rearranging the plurality of visual signs according to the at least one of transmission and reception times of the plurality of visual signs.

15. The method of claim 1 , further comprising:

storing, after the changing, edited content of conversations in an electronic file.

16. A non-transitory computer-readable recording medium having recorded thereon a program that, when executed by a computer, causes the computer to:

sequentially display, on a display unit of a first device, a plurality of visual signs according to at least one of transmission and reception times of the plurality of visual signs, the plurality of visual signs being included in a conversation between the first device and a plurality of second devices, and being transmitted between the first device and the plurality of second devices;

receive an edit mode entry command to enter an edit mode in which the plurality of visual signs are editable;

receive a visual sign selection command selecting one or more of the plurality of visual signs;

change a display order of the plurality of visual signs by moving the selected one or more of the plurality of visual signs;

fix, relative to a screen of the display unit, the moved one or more of the plurality of visual signs to a position such that the fixed one or more of the plurality of visual signs do not move in response to sequential display of additional visual signs; and

transmit, after the display order is changed, edit information indicating the movement and fixing of the selected one or more of the plurality of visual signs to only a subset of the plurality of second devices, the subset including only second devices among the plurality of second devices that have transmitted at least one of the selected one or more of the plurality of visual signs.

17. A device for providing a chat service, the device comprising:

a memory having computer-readable instructions stored therein; and

at least one processor configured to execute the computer-readable instructions to

transmit and receive a plurality of visual signs to and from a plurality of external devices,

sequentially display the plurality of visual signs on a display unit according to at least one of transmission and reception times of the plurality of visual signs,

receive an edit mode entry command to enter an edit mode in which the plurality of visual signs are editable,

receive a visual sign selection command selecting one or more of the plurality of visual signs,

change a display order of the plurality of visual signs by moving the selected one or more of the plurality of visual signs,

fix, relative to a screen of the display unit, the moved one or more of the plurality of visual signs to a position such that the fixed one or more of the plurality of visual signs do not move in response to sequential display of additional visual signs; and

transmit, after changing the display order, edit information indicating the movement and fixing of the selected one or more of the plurality of visual signs to only a subset of the plurality of external devices, the subset including only external devices among the plurality of external devices that have transmitted at least one of the selected one or more of the plurality of visual signs.