Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

…lement

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

- Use useTemplateRef API (Vue 3.5+) for panzoom wrapper ref
- Use plain variable for panzoom instance (no reactive state needed)
- Remove unnecessary null guard in initPanzoom (wrapperRef is always
  defined when called from onImageLoad)
- Add comment explaining dblclick.capture usage

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

Replace panzoom's built-in bounds option (ineffective when the panzoom
element fills its parent 100%) with manual clamping via
getBoundingClientRect. clampToBounds() is called on panend and after
each zoom to smoothly return the image within the viewport if needed.

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

- Clamp on every pan event (not just panend) for immediate stopping
- Disable smoothScroll (inertia) so the image halts on release without
  overshooting the boundary

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

smoothZoomAbs(x, y, 0) scaled the image to zero, making it disappear.
Using ZOOM_MIN (1) correctly returns the image to its original size.

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

Add rotate left (−90°) and rotate right (+90°) buttons to the image
viewer actions menu alongside the existing "Open in web browser" action.

Rotation state and controls are fully self-contained in ViewerHandlerImages:
- rotateLeft/rotateRight adjust rotation in 90° steps using unbounded angle
  increments so the CSS transition always animates in the correct direction
- Rotation resets to 0 when switching images
- ViewerHandlerImages exposes an actions array; ViewerApp renders it
  generically via component :is — no image-specific code in ViewerApp

Fixes nextcloud#1757

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-4-6

Fixes the issues found in review:

- Pan could move a letterboxed image almost entirely out of the viewport:
  bounds were clamped against the full-size wrapper instead of the image.
  Bounds are now computed from the image fit box (layout values only) —
  per axis the image is centered while it fits the container and its edges
  never leave the container edges once it exceeds it.
- Dragging at the pan boundary could freeze the viewer: clampToBounds()
  called moveTo() from the 'pan' event handler, which re-fires 'pan'
  recursively while getBoundingClientRect() still returns the pre-repaint
  geometry, so the correction never converged. The clamp now mutates the
  panzoom transform model in place inside the event handlers (applied with
  the already scheduled repaint) and cannot re-trigger events.
- Double-click zoom-out around an off-center point left the image
  displaced or off-screen: the bounds correction now re-centers the image
  on every animation frame, so it smoothly returns to the centered fit.
- After a zoom-out animation the scale settled at ~1.002..1.007 instead
  of 1 (panzoom's animation never applies the final t=1 frame), so strict
  scale === 1 checks left the viewer in a state where neither pan nor
  zoom worked. All fit checks now use an epsilon and the scale is snapped
  to exactly 1 when the zoom-out animation ends.
- Rotating an image by 90°/270° could overflow the container: the rotated
  image is now compensated to keep it fully visible.
- Container resizes re-measure the fit box and re-clamp the transform.

Signed-off-by: Vladimir Poluliashenko <vladopol@gmail.com>
Assisted-by: ClaudeCode:claude-sonnet-5