UR 2 : Time Slider

[amyburness]

2.1 As a user, I want to use a time slider to scroll through the historical and current imagery and view changes in forestation over time. (see fig 2)

Acceptance Criteria:
2.1) The user can select to view the historical Landsat or Current NICFI data.
2.3) The time slider shows the years of data available in the project for the selected data type.
2.4) The user can move the slider manually between the years and the correct image shows on the map canvas.
2.5) The user can click the play button and the plugin will cycle through the images on the map canvas while showing which year it is showing on the slider.