Merge pull request #62 from cheonjaeung/negative-spacing

Fix divide by zero crash when Adaptive's minSize is equal to spacing

Author: cheonjaeung

grid/src/commonMain/kotlin/com/cheonjaeung/compose/grid/SimpleGridCells.kt

@@ -101,7 +101,12 @@ interface SimpleGridCells {
             spacing: Int
         ): List<Int> {
             val minSizePx = minSize.roundToPx()
-            val count = max((availableSize + spacing) / (minSizePx + spacing), 1)
+            val minSizeWithSpacingPx = minSizePx + spacing
+            val count = if (minSizeWithSpacingPx != 0) {
+                max((availableSize + spacing) / minSizeWithSpacingPx, 1)
+            } else {
+                1
+            }
             val totalSpacing = spacing * (count - 1)
             val totalCellSize = availableSize - totalSpacing
             val cellSize = totalCellSize / count

grid/src/test/java/com/cheonjaeung/compose/grid/BoxGridTest.kt

@@ -747,4 +747,62 @@ class BoxGridTest {
             }
         }
     }
+
+    @Test
+    fun testNegativeSpacing() {
+        val colors = listOf(
+            Color.Blue.copy(alpha = 0.5f),
+            Color.Green.copy(alpha = 0.5f),
+            Color.Yellow.copy(alpha = 0.5f),
+            Color.Red.copy(alpha = 0.5f)
+        )
+
+        paparazzi.snapshot {
+            Column {
+                BoxGrid(
+                    modifier = Modifier
+                        .fillMaxSize()
+                        .background(Color.LightGray),
+                    rows = SimpleGridCells.Fixed(3),
+                    columns = SimpleGridCells.Fixed(3),
+                    horizontalSpacing = (-8).dp,
+                    verticalSpacing = (-16).dp
+                ) {
+                    for (row in 0 until 3) {
+                        for (column in 0 until 3) {
+                            val index = row * 3 + column
+
+                            Box(
+                                modifier = Modifier
+                                    .position(row, column)
+                                    .size(100.dp)
+                                    .background(colors[index % 4])
+                            )
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Test
+    fun testAdaptiveMinSizeEqualsNegativeSpacing() {
+        paparazzi.snapshot {
+            BoxGrid(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .background(Color.LightGray),
+                rows = SimpleGridCells.Adaptive(100.dp),
+                columns = SimpleGridCells.Adaptive(100.dp),
+                horizontalSpacing = (-100).dp,
+                verticalSpacing = (-100).dp,
+            ) {
+                Box(
+                    modifier = Modifier
+                        .size(100.dp)
+                        .background(Color.Blue)
+                )
+            }
+        }
+    }
 }

grid/src/test/java/com/cheonjaeung/compose/grid/HorizontalGridArrangementTest.kt

@@ -434,4 +434,75 @@ class HorizontalGridArrangementTest {
             }
         }
     }
+
+    @Test
+    fun testNegativeSpacedBy() {
+        paparazzi.snapshot {
+            val colors = listOf(
+                Color.Blue.copy(alpha = 0.5f),
+                Color.Green.copy(alpha = 0.5f),
+                Color.Yellow.copy(alpha = 0.5f),
+                Color.Red.copy(alpha = 0.5f)
+            )
+
+            Column {
+                HorizontalGrid(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .weight(1f)
+                        .background(Color.LightGray),
+                    rows = SimpleGridCells.Fixed(3),
+                    horizontalArrangement = Arrangement.spacedBy((-8).dp),
+                    verticalArrangement = Arrangement.spacedBy((-16).dp)
+                ) {
+                    for (i in 0 until 9) {
+                        Box(
+                            modifier = Modifier
+                                .size(100.dp)
+                                .background(colors[i % 4])
+                        )
+                    }
+                }
+
+                CompositionLocalProvider(LocalLayoutDirection provides LayoutDirection.Rtl) {
+                    HorizontalGrid(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .weight(1f)
+                            .background(Color.Gray),
+                        rows = SimpleGridCells.Fixed(3),
+                        horizontalArrangement = Arrangement.spacedBy((-8).dp),
+                        verticalArrangement = Arrangement.spacedBy((-16).dp)
+                    ) {
+                        for (i in 0 until 9) {
+                            Box(
+                                modifier = Modifier
+                                    .size(100.dp)
+                                    .background(colors[i % 4])
+                            )
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Test
+    fun testAdaptiveMinSizeEqualsNegativeSpacedBy() {
+        paparazzi.snapshot {
+            HorizontalGrid(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .background(Color.LightGray),
+                rows = SimpleGridCells.Adaptive(100.dp),
+                verticalArrangement = Arrangement.spacedBy((-100).dp),
+            ) {
+                Box(
+                    modifier = Modifier
+                        .size(100.dp)
+                        .background(Color.Blue)
+                )
+            }
+        }
+    }
 }

grid/src/test/java/com/cheonjaeung/compose/grid/VerticalGridArrangementTest.kt

@@ -434,4 +434,75 @@ class VerticalGridArrangementTest {
             }
         }
     }
+
+    @Test
+    fun testNegativeSpacedBy() {
+        paparazzi.snapshot {
+            val colors = listOf(
+                Color.Blue.copy(alpha = 0.5f),
+                Color.Green.copy(alpha = 0.5f),
+                Color.Yellow.copy(alpha = 0.5f),
+                Color.Red.copy(alpha = 0.5f)
+            )
+
+            Column {
+                VerticalGrid(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .weight(1f)
+                        .background(Color.LightGray),
+                    columns = SimpleGridCells.Fixed(3),
+                    horizontalArrangement = Arrangement.spacedBy((-8).dp),
+                    verticalArrangement = Arrangement.spacedBy((-16).dp)
+                ) {
+                    for (i in 0 until 9) {
+                        Box(
+                            modifier = Modifier
+                                .size(100.dp)
+                                .background(colors[i % 4])
+                        )
+                    }
+                }
+
+                CompositionLocalProvider(LocalLayoutDirection provides LayoutDirection.Rtl) {
+                    VerticalGrid(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .weight(1f)
+                            .background(Color.Gray),
+                        columns = SimpleGridCells.Fixed(3),
+                        horizontalArrangement = Arrangement.spacedBy((-8).dp),
+                        verticalArrangement = Arrangement.spacedBy((-16).dp)
+                    ) {
+                        for (i in 0 until 9) {
+                            Box(
+                                modifier = Modifier
+                                    .size(100.dp)
+                                    .background(colors[i % 4])
+                            )
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Test
+    fun testAdaptiveMinSizeEqualsNegativeSpacedBy() {
+        paparazzi.snapshot {
+            VerticalGrid(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .background(Color.LightGray),
+                columns = SimpleGridCells.Adaptive(100.dp),
+                horizontalArrangement = Arrangement.spacedBy((-100).dp),
+            ) {
+                Box(
+                    modifier = Modifier
+                        .size(100.dp)
+                        .background(Color.Blue)
+                )
+            }
+        }
+    }
 }