The most comfortable way to exploit the functionalities of the View Server (VS)
is via the built-in web client. This client provides an intuitively to use
is via the built-in `web client <https://github.com/eoxc/prism>`_ based on `eoxc <https://github.com/eoxc/eoxc>`_ library. This client provides an intuitively to use
interactive graphical user interface running in the user's web browser.
.. _fig_webclient:
.. figure:: images/webclient_start.*
:alt: Screenshot of View Server built-in Web Client
*View Server built-in Web Client*
:numref:`fig_webclient` above shows the basic interface
When the web client is opened for the first time a short interactive tutorial starts. It should guide you through some of main features and elements. You can start this intro again clicking the *book* icon in the bottom right of the window.
Interactive Tutorial
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@@ -21,54 +15,101 @@ Interactive Tutorial
*Web Client Tutorial - Start*
Map
---
The main map view is for visualization and browsing through existing satellite image data catalog.
Navigate to your area of interest by:
* *panning*: using left click + drag or one finger drag and two finger pinch
* *zooming*: using mouse wheel scroll, double click or plus and minus icons in bottom right corner of a map
While hovering over the footprints in the map, the respective product(s) are highlighted in the map, timeslider and the selection menu on the right.
Clicking on the footprints in the map and then clicking on the plus or minus button overlays can used to add or remove images to/from selection for the download (see Download below).
In the top most part of the map, there is a colored loading indicator bar spanning the full width of the window, making it easier to understand if loading all requested map tiles is already finished or still in progress.
There are two side panels: the left menu for layer selection, filters and right menu for listing available data entries, adding them to download selection and downloading.
You can also easily view current map layer view without any UI features of the web client by clicking on the *landscape map* icon in the bottom right of the map window. Clicking on this button opens a list of available layers. Another click on one of them opens a new browser tab with a created WMS request copying current map parameters (zoom, bounding box, selected time, styling etc).
.. figure:: images/webclient_tutorial_02_map.*
:alt: Web Client Tutorial - Map
*Web Client Tutorial - Map*
Timeslider
----------
Timeslider presents the distribution and number of datasets in time via *bar* graph or *aggregated dots* graph. Visualization mode used (*bars* or *dots*) is based on current total number of products for given time frame. You can use Timeslider tool in following ways:
* panning: on the bottom area (left click + drag) or left and right arrow icons on sides
* zooming: mouse wheel scroll or two finger pinch or plus and minus icons in the middle
* reloading: click on spinner icon in the middle
* selecting a time interval: in the upper area left click + drag or one finger drag or click on histogram bucket
* showing total number of available products in histogram bucket: hover over histogram bucket
* showing fooprints of all products, first product id and total number of additional products in a dot group: hover over dot group
* showing start and end of current selection: left click + hold on selection rectangle
* zooming a map to a combined bounding box of all products in a dot group: click on dot group
Clicking on the *link* button next to the level in the search result tab, it is possible to save the search query. To download the XML file click with the right mouse button on the link and then "Save Link As...".
Filters
-------
There are several possibilities to filter queried satellite data in the *Filters* panel on left side of the window:
1. Spatial query: with Spatial Filter using the Point, Rectangle or Polygon drawing options under *Draw*. By default when no spatial filter is set, current map window extent is used as a spatial filter.
2. Temporal query with Timeslider tool: Enter Start and End date of your search interval. More information provided in Timeslider section of documentation.
3. You can apply additional filters for each layer based on available metadata under "Additional filters" as configured by the operator. Currently "cloud coverage percentage" filter is set up.
*Layers* panel on left side enables setting the *Overlay*, *Layer* and *Base Layer* groups currently visualized.
*Web Client Tutorial - Map Layers*
*Base Layer* and *Overlay* groups enable choosing the background, text labels and other footprints to be viewed on the map window for easier orientation.
Map
---
*Layer* group presents selected data sets and its products or products levels (e.g. VHR Image 2018 Level 1).
You can change the order of the layers by dragging the arrows corresponding to each layer up and down. This influences the order of rendering on the map and order of representation of datasets in Timeslider.
Timeslider
----------
Layers can be fully disabled and enabled by the *eye* icon next to its name.
Changing the visualization (styling) of layers can be adapted by clicking on the *paint brush* icon next to the layer name. An afterwards displayed popup window enables setting the opacity and one of pre-configured styles for the layer.
