Viewport Grid Service
Overview
This is a new UI service, that handles the grid layout of the viewer.
Events
There are seven events that get publish in ViewportGridService :
| Event | Description | 
|---|---|
| ACTIVE_VIEWPORT_INDEX_CHANGED | Fires the index of the active viewport is changed | 
| LAYOUT_CHANGED | Fires the layout is changed | 
| GRID_STATE_CHANGED | Fires when the entire grid state is changed | 
Interface
For a more detailed look on the options and return values each of these methods
is expected to support, [check out it's interface in @ohif/core][interface]
| API Member | Description | 
|---|---|
setActiveViewportIndex(index) | Sets the active viewport index in the app | 
getState() | Gets the states of the viewport (see below) | 
setDisplaySetsForViewport({ viewportIndex, displaySetInstanceUID }) | Sets displaySet for viewport based on displaySet Id | 
setLayout({numCols, numRows, keepExtraViewports}) | Sets rows and columns. When the total number of viewports decreases, optionally keep the extra/offscreen viewports. | 
reset() | Resets the default states | 
getNumViewportPanes() | Gets the number of visible viewport panes | 
getLayoutOptionsFromState(gridState) | Utility method that produces a ViewportLayoutOptions based on the passed in state | 
Implementations
| Implementation | Consumer | 
|---|---|
| [ViewportGridProvider] | Baked into Dialog Provider | 
* - Denotes maintained by OHIF
State
const DEFAULT_STATE = {
  // starting from null, hanging
  // protocol will defined number of rows and cols
  numRows: null,
  numCols: null,
  viewports: [
    /*
     * {
     *    displaySetInstanceUID: string,
     * }
     */
  ],
  activeViewportIndex: 0,
};