Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for animating a drag gesture are disclosed. In one aspect, a method includes the actions of receiving a user input that drags a user interface element along a user-induced path across a display. The actions further include moving the user interface element along the user-induced path across the display. The actions further include determining that the user input has ceased. The actions further include determining an additional path and a speed for the user interface element to move along the additional path based on the user-induced path and a speed of the user input. The actions further include moving the user interface element along the additional path to a resting location at the determined speed for the user interface element to move along the additional path.

Abstract: Aspects of the subject technology relate to systems and methods for constraints-based layout and control of user interface (UI) elements. The system receives a first user input indicating an instruction to position a first UI element on a page of the layout application. The system receives a second user input indicating an instruction to position a second UI element on the page. The system receives a third user input indicating an instruction to create a connection from the second UI element to the first UI element. The system generates a layout constraint indicating a spatial relationship between the first UI element and the second UI element based on the connection. The system provides the layout constraint in a layout data file associated with the UI.

Abstract: Aspects of the subject technology relate to systems and methods for constraints-based layout and control of user interface elements. The system receives a first user input indicating an instruction to position a first UI element on a page of the layout application. The system receives a second user input indicating an instruction to position a second UI element on the page. The system receives a third user input indicating an instruction to create a connection from the second UI element to the first UI element. The system generates a layout constraint indicating a spatial relationship between the first UI element and the second UI element based on the connection. The system provides the layout constraint in a layout data file associated with the UI.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for animating a drag gesture are disclosed. In one aspect, a method includes the actions of receiving a user input that drags a user interface element along a user-induced path across a display. The actions further include moving the user interface element along the user-induced path across the display. The actions further include determining that the user input has ceased. The actions further include determining an additional path and a speed for the user interface element to move along the additional path based on the user-induced path and a speed of the user input. The actions further include moving the user interface element along the additional path to a resting location at the determined speed for the user interface element to move along the additional path.

Abstract: Aspects of the subject technology relate to systems and methods for representing complex constraints on widgets for a user interface, using a small set of common rules allowing developers to represent arbitrary one-to-one relationships between widgets. A layout tool may be provided that, in operation, displays a layout area to a developer. The layout tool may include a user interface (UI) inference engine that, when one or more widgets are placed and/or moved within the layout area, generates inferred constraints for the one or more widgets. These inferred constraints may be generated, with or without further input from the developer, based on the relative positions of the one or more widgets in the layout area. An infer-constraints button may be provided that, when selected following placement of widgets in the layout area, causes generation of inferred constraints for each of the widgets.

Abstract: Aspects of the subject technology relate to systems and methods for constraints-based layout and control of user interface elements. The system receives a first user input indicating an instruction to position a first UI element on a page of the layout application. The system receives a second user input indicating an instruction to position a second UI element on the page. The system receives a third user input indicating an instruction to create a connection from the second UI element to the first UI element. The system generates a layout constraint indicating a spatial relationship between the first UI element and the second UI element based on the connection. The system provides the layout constraint in a layout data file associated with the UI.

Abstract: Aspects of the subject technology relate to systems and methods for representing complex constraints on widgets for a user interface, using a small set of common rules allowing developers to represent arbitrary one-to-one relationships between widgets. A layout tool may be provided that, in operation, displays a layout area to a developer. The layout tool may include a user interface (UI) inference engine that, when one or more widgets are placed and/or moved within the layout area, generates inferred constraints for the one or more widgets. These inferred constraints may be generated, with or without further input from the developer, based on the relative positions of the one or more widgets in the layout area. An infer-constraints button may be provided that, when selected following placement of widgets in the layout area, causes generation of inferred constraints for each of the widgets.