Fix rethrowing cancellation exceptions (#563)

* Fix missing import

* Rethrow cancellation-exceptions

Author: mlykotom

compose/snippets/src/androidTest/java/com/example/compose/snippets/semantics/SemanticsSnippets.kt

@@ -16,6 +16,7 @@
 
 package com.example.compose.snippets.semantics
 
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.semantics.SemanticsProperties

compose/snippets/src/main/java/com/example/compose/snippets/animations/sharedelement/CustomizeSharedElementsSnippets.kt

@@ -659,7 +659,7 @@ fun CustomPredictiveBackHandle() {
                 // For each backEvent that comes in, we manually seekTo the reported back progress
                 try {
                     seekableTransitionState.seekTo(backEvent.progress, targetState = Screen.Home)
-                } catch (e: CancellationException) {
+                } catch (_: CancellationException) {
                     // seekTo may be cancelled as expected, if animateTo or subsequent seekTo calls
                     // before the current seekTo finishes, in this case, we ignore the cancellation.
                 }
@@ -671,6 +671,7 @@ fun CustomPredictiveBackHandle() {
             // When the predictive back gesture is cancelled, we snap to the end state to ensure
             // it completes its seeking animation back to the currentState
             seekableTransitionState.snapTo(seekableTransitionState.currentState)
+            throw e
         }
     }
     val coroutineScope = rememberCoroutineScope()

compose/snippets/src/main/java/com/example/compose/snippets/predictiveback/PredictiveBackSnippets.kt

@@ -37,6 +37,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.TransformOrigin
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.input.pointer.util.VelocityTracker
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
@@ -110,7 +111,10 @@ private fun PredictiveBackHandlerBasicExample() {
 
     Box(
         modifier = Modifier
-            .fillMaxSize(boxScale)
+            .graphicsLayer {
+                scaleX = boxScale
+                scaleY = scaleX
+            }
             .background(Color.Blue)
     )
 
@@ -127,6 +131,7 @@ private fun PredictiveBackHandlerBasicExample() {
         } catch (e: CancellationException) {
             // code for cancellation
             boxScale = 1F
+            throw e
         }
     }
     // [END android_compose_predictivebackhandler_basic]
@@ -180,8 +185,10 @@ private fun PredictiveBackHandlerManualProgress() {
                 closeDrawer(velocityTracker.calculateVelocity().x)
             } catch (e: CancellationException) {
                 openDrawer(velocityTracker.calculateVelocity().x)
+                throw e
+            } finally {
+                velocityTracker.resetTracking()
             }
-            velocityTracker.resetTracking()
         }
         // [END android_compose_predictivebackhandler_manualprogress]
     }