Frames are the second lowest instance in the task hierarchy. For each trial, a series of frames will be shown during experiment execution. Frames are created within each trial group, hence different trialgroups have completely independent frame sequences. Events within trials can then modify the frame properties and objects on each frame. Typically, one trialgroup has several frames. The different frames are presented sequentially by default upon experiment execution, but the order can also be completely customized by using the event system.
Frames can be deleted, copied, and imported from other tasks / studies. Similar to how tasks are imported, when importing frames, you have to specify how each variable should be used on the newly copied frame. You can choose either to copy it (create a new one) or re-use it (link it to the existing one). The default order of frames can be changed by dragging each frame to a specified position. The "current selected frame" can be chosen via a mouse click and is shown in the center of the task editor.
There are two different frame types: canvas frames and page frames. They can be intermixed in each trialgroup (although many times it will make sense to keep them separate). Both can be added to the current selected trial group via a click on the respective icons in the "Trial Timeline". Both canvas and page frames share a few frame properties, which are:
- Name (String): Name of the frame.
- Duration (Enabled/Disabled): If enabled, one can specify a fixed display duration for the current frame in milliseconds. After this time is over, the next frame will be shown automatically. This is an easy way to move participants to the next frame. However, if you choose to use duration, it is not recommended that you also use an event to move participants to the next frame or other frames. Enabling this option is only recommended if the frame duration is always fixed and there is no custom "Jump To" event to jump to a different frame.
- Color (Hex-String): Background color of the frame.
- Hide Mouse: (Enabled/Disabled): If enabled, the mouse will not be shown to participants during the frame execution.
Differences Between Canvas and Page Frames
Canvas and page frames differ in various ways. Most importantly, on a canvas frame, objects can be positioned freely, rescaled, and modified using drag & drop. Users can also zoom in and out on canvas frames. Optional auxiliary lines, called grid lines, help to position the objects evenly and can be shown or hidden in the editor (click the checkbox below the frame). The canvas frame allows you to edit your content very uniquely.
Page frames are used mainly to create questionnaires, which can be designed very efficiently by a pre-defined layout. Objects on a page frame cannot be positioned freely, but instead automatically flow below each other to create a list format. The vertical ordering of elements can be changed easily using drag & drop methods. Instead of zooming in and out, one can scroll up and down using the mouse-wheel. Also, instead of auxiliary grid lines, one can activate a preview mode to see show a page frame will look like during experiment execution (checkbox below the frame).
A further difference is that media objects such as images, videos, and audio files can only be added to the canvas frame. However, by using the text editor (above the current frame), images can be inserted within text elements and thereby also appear on a page frame. The two types of frames also have a few different general properties, described in the next sections.
Special Canvas Frame Properties
- Frame Height (Numeric): Determines the height of the frame in Design Units.
- Frame Width (Numeric): Determines the width of the frame in Design Units.
Special Page Frame Properties
- Max-Width (Numeric): Determines the maximum width of the frame in Pixels.
- Border-Size (Numeric): Determines the border size of elements within the page frame.
- Element Margin (Numeric): Determines the lower margin of elements within the page frame.
All frames in the selected trial group are shown in the "Trial Timeline" (bottom center of the task editor). The frame which was clicked on last is the current selected frame and its content is shown in the center frame. Objects and events can be added separately to each frame. The "properties" of the current selected frame are shown to the right of the Trial Timeline. The order of frames can be changed using drag & drop methods. Existing frames can be can be copied, deleted and imported.