loon - user interface gestures

Introduction

The keyboard and mouse gestures for the graphical user interfaces of loon's displays should be fairly easy to learn. We kept the number of mouse gestures and keyboard shortcuts minimal. The Ctrl and Shift in combination with the left and right mouse button or mouse wheel is all you ever need. In fact, the default gestures for the scatterplot display are summarized by the following figures.

Zoom and Pan gestures are as follows (the serialaxes display does not support zoom and pan)

Two superimposed mice illustrate a click and drag gesture

The selection gestures are as follows

Two superimposed mice illustrate a click and drag gesture

And for the scatterplot display one can temporary move points as follows

Move points on scatterplot

MacBook Trackpad

Note that for the MacBook trackpad the right button press and drag events can be configured in Settings > Trackpad with the Secondary click setting, see image below. For example, when set to "Click or tab with two fingers" then a two-finger-press and drag movement while keeping the fingers pressed will generate the right-click dragging events (e.g. for panning). There is also a Scroll and Zoom tab to specify the zoom event (usually a two-finger vertical swipe gesture).

User Interface Behavior

There are a few things which are good to know and are features rather than bugs.

Inspector

• Only one loon inspector at a time can be open at a given time. If you would like to deactivate the loon inspector set the useLoonInspector state to FALSE (R-Code)

  p <- l_plot(iris, useLoonInspector=FALSE)
  pi <- l_plot_inspector(activewidget=p)

Resizing Points

• Points with size less equal 1 are shown with the same glyph size.
• Absolute resizing will use the minimum size of the selected points to determine the new size for all selected points.
• Relative resizing will add or subtract one size unit for each selected point.
• Decreasing the size of the selected points using the inspector will stop responding to button presses if any of the selected points is less equal than zero.

Layers

• Only the model layer is interactive!
• The button toolbar in the layers window has the functionality as follows: and move a layer or drawing one position up or down among the children of its parent. The moves the layer or drawing to the grand parent layer and the button moves the selected layer or drawing into the layer directly below it if the item below the selected element is a layer. and turn the selected drawing or layer and all its children visible and invisible, respectively. adds a new layer and removes the selected element where it is a layer it will delete all its children. Finally, scales the plot such that the selected layer is completely shown.

Modifier Keys

The default modifier keys used in loon are Ctrl and Shift. Sometimes operating systems use some of these modifier keys for system functions and hence wont pass their respective key events to Tk. Also, different operating systems generate different events for the mouse scroll wheel. If you experience problems with the above mentioned gestures please try each gesture on the eventutil below and which events do no get generated on your system:

In Tcl

::loon::eventsutil

Or in R

.Tcl('::loon::eventsutil')