Controlling multitasking application displays using gestures

A display processing device comprising:

• a sensor operative to receive a first gesture operation on a touch display region of an electronic device when a first application interface of a first application installed in the electronic device is displayed in the touch display region;
• a processor operative to determine whether the first gesture operation satisfies a first predetermined condition or not by determining whether the first gesture operation is an upward sliding operation that starts from a first position and ends at a second position defined to be positioned upward of the first position, to generate a first sub interface to be displayed in a first sub region of the touch display region, and to generate a second sub interface to be displayed in a second sub region of the touch display region when it is determined that the first gesture operation satisfies the first predetermined condition, wherein the first sub region is located upward relative to the second sub region, and wherein the first sub interface corresponds to the first application interface and the second sub interface corresponds to a second application interface of a second application installed in the electronic device, wherein both the first application interface and the second application interface are interfaces of activated applications;
• a display operative to display the first sub interface in the first sub region and to display the second sub interface in the second sub region, wherein with the upward sliding operation of the first gesture operation, the first sub interface gradually zooms out in an upward direction, and at the same time the second sub interface gradually emerges in the upward direction from a lower edge of the electronic device, wherein the second sub region is located upward of the lower edge of the electronic device;
• wherein
• the sensor is further operative to receive a second gesture operation on the touch display region after displaying the first sub interface in the first sub region and displaying the second sub interface in the second sub region;
• the processor is further operative to determine whether the second gesture operation satisfies a second predetermined condition or not, to generate a third sub interface to be displayed in the first sub region of the touch display region, and to generate a fourth sub interface to be displayed in the second sub region of the touch display region when it is determined that the second gesture operation satisfies the second predetermined condition, wherein the third sub interface corresponds to the second application interface and the fourth sub interface corresponds to a third application interface of a third application installed in the electronic device;
• the display is further operative to display the third sub interface in the first sub region and to display the fourth sub interface in the second sub region;
• the sensor is further operative to receive a fourth gesture operation on the touch display region after displaying the first sub interface in the first sub region and displaying the second sub interface in the second sub region;
• the processor is further operative to determine whether the fourth gesture operation satisfies a fourth predetermined condition or not which comprises determining whether an initial touch point of the fourth gesture operation on the touch display region is located in the second sub region;
• and
• the display is further operative to display only the second application interface in the touch display region when it is determined that the fourth gesture operation satisfies the fourth predetermined condition.