Reimplement camera gestures

[sargunv]

Once we integrate with the native core, we'll lose SDK gestures on iOS, Android, and Desktop. Once we set zIndex to a negative value on web (to support Compose overlays), we'll lose SDK gestures there too.

We should reimplement gestures in Compose with pointerInput. #216 has a draft implementation of this, with pan, zoom, and rotate. This issue serves as a place to note requirements for the real version we'll build after #218. It's the ideal goal; unsure how much will be possible in Compose.

• (Multi) touch screens
  • Single finger drag pan
  • Two finger pinch zoom
  • Two finger rotation
  • Two finger "shove" tilt
  • Double tap and release animated zoom in
  • Double tap and drag "quick" zoom in and out
• Multi-touch trackpads
  • Two finger "scroll" pan
    • if disabled, vertical scroll should work the same as mouse scroll (zoom)
  • Two finger pinch zoom
  • Two finger rotation
• Mouse and keyboard
  • Click and drag pan
  • Double click animated zoom in
  • Scroll zoom in and out
  • Cmd/Ctrl +/- zoom in and out
  • Secondary click and drag rotate (x) and tilt (y)
  • Shift click and drag zoom
  • Option/Alt click and drag rotate (x) and tilt (y)
• Zoom and rotate should operate around the centroid of the touch inputs (affecting offset appropriately)
• Pan, zoom, rotate, and tilt should have some fling velocity, with non-pan motion decaying much faster than pan
• All gestures should be supported on all platforms (if possible), as desktop may have touch screens, mobile may be connected to a mouse and keyboard, and browsers exist on both
• Decay, keyboard keys, active state of each gesture, and direction of quick zoom should be configurable

cc @westnordost did I miss anything?

[westnordost]

Regarding keyboard:

Usually one can...

• move the view with ←↑↓→
• rotate the view withShift + ←→
• tilt the view with Shift + ↑↓
• zoom the view with +-

Ctrl is usually only necessary for move and zoom when the map is embedded as an iframe within a website, i.e. more generally, if it is within a scrollable area.

Regarding mouse:

For right-mouse-button or Shift + mouse button, there is no expected standard behavior: Holding the right-mouse-button sometimes is used to rotate + tilt. But on maps that show a context menu on right-mouse-button click, the right mouse button usually has no gesture function. Instead, Shift + left-mouse-button is rotate + tilt.

For both MapBox and MapLibre it is possible to select an area with Shift + left-mouse-button in which the view should zoom into.

Ctrl is usually necessary for any mouse gesture when the map is embedded as an iframe within a website, i.e. more generally, if it is within a scrollable area.

[sargunv]

move the view with ←↑↓→
rotate the view withShift + ←→
tilt the view with Shift + ↑↓
zoom the view with +-

sgtm. for keyboard-only controls, we should probably consider focus.

Ctrl is usually only necessary for move and zoom when the map is embedded as an iframe within a website, i.e. more generally, if it is within a scrollable area.

we probably don't need to handle this, beyond making it easy to configure in our public API.

For right-mouse-button or Shift + mouse button, there is no expected standard behavior: Holding the right-mouse-button sometimes is used to rotate + tilt. But on maps that show a context menu on right-mouse-button click, the right mouse button usually has no gesture function. Instead, Shift + left-mouse-button is rotate + tilt.

Investigating other maps:

• Apple Maps (macOS)
  • Option + left mouse drag is rotate and tilt
  • Right click is a context menu
• Google Maps (Chrome)
  • Option + left mouse drag is rotate and tilt
  • Shift + left mouse drag is rotate and tilt
  • Control + left mouse drag is rotate and tilt
  • Right click is a context menu
• Mapbox (Chrome)
  • Right mouse drag is rotate and tilt
  • Control + left mouse drag is rotate and tilt
  • Shift + left mouse drag is select a view to zoom in to

I think I like the Mapbox defaults, but configuration API should allow for Google/Apple-like behavior