guarantee camera trigger mode is recorded with a template method

src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineDispim.java

@@ -633,7 +633,7 @@ private boolean doHardwareCalculations(PLogicDispim plc) {
         boolean changeChannelPerVolumeSoftware = false;
         boolean changeChannelPerVolumeDoneFirst = false;
         if (acqSettings_.channels().enabled()) {
-            if (acqSettings_.channels().count() > 1) {
+            if (acqSettings_.channels().count() == 0) {
                 studio_.logs().showError("\"Channels\" is checked, but no channels are selected");
                 return false; // early exit
             }
@@ -650,14 +650,14 @@ private boolean doHardwareCalculations(PLogicDispim plc) {
                         // we have at least 2 channels
                         // intentionally leave extraChannelOffset_ untouched so that it can be specified by user by choosing a preset
                         //   for the channel in the main Micro-Manager window
+                        final boolean success = plc.setupHardwareChannelSwitching(acqSettings_);
+                        if (!success) {
+                            studio_.logs().showError("Couldn't set up slice hardware channel switching.");
+                            return false; // early exit
+                        }
+                        nrChannelsSoftware = 1;
+                        nrSlicesSoftware = acqSettings_.volume().slicesPerView() * acqSettings_.channels().count();
                     }
-                    final boolean success = plc.setupHardwareChannelSwitching(acqSettings_);
-                    if (!success) {
-                        studio_.logs().showError("Couldn't set up slice hardware channel switching.");
-                        return false; // early exit
-                    }
-                    nrChannelsSoftware = 1;
-                    nrSlicesSoftware = acqSettings_.volume().slicesPerView() * acqSettings_.channels().count();
                     break;
                 default:
                     studio_.logs().showError(
@@ -762,7 +762,7 @@ public void recalculateSliceTiming() {
                 CameraBase camera = model_.devices().device("ImagingCamera");
                 camera.setTriggerMode(acqSettings_.cameraMode());
                 studio_.logs().logDebugMessage(
-                        "camera \"" + camera.getDeviceName() + "\" set to mode: " + camera.getTriggerMode());
+                        "camera \"" + camera.getDeviceName() + "\" requested mode: " + camera.getTriggerMode());
             }
             return;
         }

src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineScape.java

@@ -174,13 +174,6 @@ boolean run() {
                     studio_.logs().showError("Must have stage with scan-enabled firmware for stage scanning.");
                     return false;
                 }
-                if (acqSettings_.acquisitionMode() == AcquisitionMode.STAGE_SCAN_INTERLEAVED) {
-                    if (acqSettings_.volume().numViews() < 2) {
-                        studio_.logs().showError("Interleaved stage scan requires two sides.");
-                    }
-                    return false;
-                }
-
                 // second part: initialize stage scanning, so we can restore state later
                 xyPosUm_ = xyStage.getXYPosition();
                 origSpeedX_ = xyStage.getSpeedX();
@@ -873,7 +866,7 @@ private boolean doHardwareCalculations(PLogicScape plc) {
         for (CameraBase camera : cameras) {
             camera.setTriggerMode(acqSettings_.cameraMode());
             studio_.logs().logMessage("camera \"" + camera.getDeviceName()
-                 + "\" set to mode: " + camera.getTriggerMode());
+                 + "\" requested mode: " + camera.getTriggerMode());
         }
 
         // make sure slice timings are up-to-date

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/AndorCamera.java

@@ -50,8 +50,7 @@ public AndorCamera(Studio studio, String deviceName) {
     }
 
     @Override
-    public void setTriggerMode(CameraMode cameraMode) {
-        mode_ = cameraMode;
+    protected void applyTriggerMode(CameraMode cameraMode) {
         // work-around a bug in SDK3 device adapter, can't switch from light sheet mode
         //  to "normal" center out simultaneous but works if we always go through the in-between mode
         if (hasProperty(Properties.SENSOR_READOUT_MODE)) {

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/CameraBase.java

@@ -11,8 +11,14 @@
  * This is the base camera class.
  *
  * <p>Methods that need per-vendor knowledge are abstract on purpose: a camera class that
- * forgets one fails to compile. Cameras whose device library resolves to
- * {@code CameraLibrary.UNKNOWN} use {@link UnknownCamera}.
+ * forgets one fails to compile.
+ *
+ * <p>Trigger mode is the exception: implement {@link #applyTriggerMode}, which only has to write
+ * the mode to the device. {@link #setTriggerMode} is final and records it here for
+ * {@link #getTriggerMode}, so no vendor has to maintain it.
+ *
+ * <p>Cameras whose device library resolves to {@code CameraLibrary.UNKNOWN} use
+ * {@link UnknownCamera}.
  */
 public abstract class CameraBase extends DeviceBase implements LightSheetCamera {
 
@@ -239,13 +245,32 @@ public int roiReadoutRowsSplitReadout(Rectangle roi, Rectangle sensor) {
 
     // needed for subclasses
 
+    /**
+     * Sets the camera trigger mode and records it.
+     *
+     * <p>Final because the recorded mode is base state, which a vendor override would have to
+     * remember to maintain. Vendors implement {@link #applyTriggerMode} instead.
+     */
     @Override
-    public void setTriggerMode(CameraMode cameraMode) {
+    public final void setTriggerMode(final CameraMode cameraMode) {
+        applyTriggerMode(cameraMode);
         mode_ = cameraMode;
     }
 
+    /**
+     * Writes the trigger mode to the device.
+     */
+    protected abstract void applyTriggerMode(final CameraMode cameraMode);
+
+    /**
+     * Returns the last mode requested through {@link #setTriggerMode}.
+     *
+     * <p>This is not a device readback because the vendor mapping from camera mode to device
+     * properties is not always reversible, so the requested mode is the only answer every camera
+     * can give.
+     */
     @Override
-    public CameraMode getTriggerMode() {
+    public final CameraMode getTriggerMode() {
         return mode_;
     }
 

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/DemoCamera.java

@@ -25,7 +25,7 @@ public DemoCamera(Studio studio, String deviceName) {
     }
 
     @Override
-    public void setTriggerMode(final CameraMode cameraMode) {
+    protected void applyTriggerMode(final CameraMode cameraMode) {
         // do nothing - no camera trigger modes - always internal - log for debug convenience
         studio_.logs().logMessage(
                 "setTriggerMode(" + cameraMode + ") called but the DemoCamera is always in internal mode.");

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/HamamatsuCamera.java

@@ -55,8 +55,7 @@ public HamamatsuCamera(final Studio studio, final String deviceName) {
     }
 
     @Override
-    public void setTriggerMode(final CameraMode cameraMode) {
-        mode_ = cameraMode;
+    protected void applyTriggerMode(final CameraMode cameraMode) {
         setProperty(Properties.TRIGGER_SOURCE, (cameraMode == CameraMode.INTERNAL) ? Values.INTERNAL : Values.EXTERNAL);
         setProperty(Properties.SENSOR_MODE, (cameraMode == CameraMode.VIRTUAL_SLIT) ? Values.PROGRESSIVE : Values.AREA);
         switch (cameraMode) {

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/PcoCamera.java

@@ -38,8 +38,7 @@ public PcoCamera(Studio studio, String deviceName) {
     }
 
     @Override
-    public void setTriggerMode(CameraMode cameraMode) {
-        mode_ = cameraMode;
+    protected void applyTriggerMode(CameraMode cameraMode) {
         switch (cameraMode) {
             case EDGE:
             case PSEUDO_OVERLAP:

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/PvCamera.java

@@ -43,7 +43,7 @@ public PvCamera(final Studio studio, final String deviceName) {
     }
 
     @Override
-    public void setTriggerMode(final CameraMode cameraMode) {
+    protected void applyTriggerMode(final CameraMode cameraMode) {
         switch (cameraMode) {
             case EDGE:
             case PSEUDO_OVERLAP:
@@ -58,11 +58,6 @@ public void setTriggerMode(final CameraMode cameraMode) {
         }
     }
 
-    @Override
-    public CameraMode getTriggerMode() {
-        return CameraMode.fromString(getProperty(Properties.TRIGGER_MODE));
-    }
-
     @Override
     public void setBinning() {
 

src/main/java/org/micromanager/lightsheetmanager/model/devices/cameras/UnknownCamera.java

@@ -26,6 +26,11 @@ private UnsupportedOperationException unsupported(final String what) {
                 + " is unknown. Supported: AndorSDK3, HamamatsuHam, PCO_Camera, PVCAM, DemoCamera.");
     }
 
+    @Override
+    protected void applyTriggerMode(final CameraMode cameraMode) {
+        throw unsupported("trigger mode");
+    }
+
     @Override
     public void setBinning() {
         throw unsupported("binning");

src/main/java/org/micromanager/lightsheetmanager/model/utils/NumberUtils.java

@@ -48,6 +48,7 @@ public static double roundToPlace(final double value, final int place) {
     /**
      * Return the double value rounded up to the nearest increment of 0.25.
      * <p>Example: 0.0 goes to 0.0 but 0.01 goes to 0.25
+     * <p>Quarter milliseconds are the timing quantum because the PLogic evaluates its cells at 4kHz.
      *
      * @param value the value to round up
      * @return the value rounded up
@@ -58,6 +59,7 @@ public static double ceilToQuarterMs(final double value) {
 
     /**
      * Return the double value rounded to the nearest increment of 0.25.
+     * <p>Quarter milliseconds are the timing quantum because the PLogic evaluates its cells at 4kHz.
      *
      * @param value the value to round
      * @return the rounded value