Merge pull request #170 from mP1/feature/SpreadsheetExpressionFunctio…

…nObjectCellStyle

SpreadsheetExpressionFunctionObjectCellStyle

src/main/java/walkingkooka/spreadsheet/expression/function/SpreadsheetExpressionFunctionObjectCellStyle.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2022 Miroslav Pokorny (github.com/mP1)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package walkingkooka.spreadsheet.expression.function;
+
+import walkingkooka.spreadsheet.expression.SpreadsheetExpressionEvaluationContext;
+import walkingkooka.tree.expression.function.ExpressionFunctionParameter;
+
+import java.util.List;
+
+/**
+ * A custom function that retrieves the {@link walkingkooka.tree.text.TextStyle} for the current cell.
+ * This function exists primarily to support filtering cells using a predicate of the current cell.
+ */
+final class SpreadsheetExpressionFunctionObjectCellStyle extends SpreadsheetExpressionFunctionObject {
+
+    /**
+     * Singleton
+     */
+    final static SpreadsheetExpressionFunctionObjectCellStyle INSTANCE = new SpreadsheetExpressionFunctionObjectCellStyle();
+
+    private SpreadsheetExpressionFunctionObjectCellStyle() {
+        super("cellStyle");
+    }
+
+    @Override
+    public List<ExpressionFunctionParameter<?>> parameters(final int count) {
+        return ExpressionFunctionParameter.EMPTY;
+    }
+
+    @Override
+    public Object apply(final List<Object> parameters,
+                        final SpreadsheetExpressionEvaluationContext context) {
+        this.checkParameterCount(parameters);
+
+        return context.cellOrFail()
+                .style();
+    }
+}

src/main/java/walkingkooka/spreadsheet/expression/function/SpreadsheetExpressionFunctionProviders.java

@@ -56,6 +56,7 @@ public static ExpressionFunctionProvider expressionFunctionProvider(final CaseSe
                                 SpreadsheetExpressionFunctions.bitXor(),
                                 SpreadsheetExpressionFunctions.ceil(),
                                 SpreadsheetExpressionFunctions.cell(),
+                                SpreadsheetExpressionFunctions.cellStyle(),
                                 SpreadsheetExpressionFunctions.cellValue(),
                                 SpreadsheetExpressionFunctions.charFunction(),
                                 SpreadsheetExpressionFunctions.choose(),

src/main/java/walkingkooka/spreadsheet/expression/function/SpreadsheetExpressionFunctions.java

@@ -171,6 +171,13 @@ public static ExpressionFunction<Object, SpreadsheetExpressionEvaluationContext>
         return SpreadsheetExpressionFunctionObjectCell.INSTANCE;
     }
 
+    /**
+     * {@see SpreadsheetExpressionFunctionObjectCellStyle}
+     */
+    public static ExpressionFunction<Object, SpreadsheetExpressionEvaluationContext> cellStyle() {
+        return SpreadsheetExpressionFunctionObjectCellStyle.INSTANCE;
+    }
+
     /**
      * {@see SpreadsheetExpressionFunctionObjectCellValue}
      */

src/test/java/walkingkooka/spreadsheet/expression/function/SpreadsheetExpressionFunctionObjectCellStyleTest.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2022 Miroslav Pokorny (github.com/mP1)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package walkingkooka.spreadsheet.expression.function;
+
+import org.junit.jupiter.api.Test;
+import walkingkooka.collect.list.Lists;
+import walkingkooka.spreadsheet.SpreadsheetCell;
+import walkingkooka.spreadsheet.SpreadsheetFormula;
+import walkingkooka.spreadsheet.expression.FakeSpreadsheetExpressionEvaluationContext;
+import walkingkooka.spreadsheet.reference.SpreadsheetSelection;
+import walkingkooka.tree.text.TextAlign;
+import walkingkooka.tree.text.TextStyle;
+import walkingkooka.tree.text.TextStylePropertyName;
+
+import java.util.Optional;
+
+public final class SpreadsheetExpressionFunctionObjectCellStyleTest extends SpreadsheetExpressionFunctionObjectTestCase<SpreadsheetExpressionFunctionObjectCellStyle> {
+
+    @Test
+    public void testApply() {
+        final TextStyle style = TextStyle.EMPTY.set(
+                TextStylePropertyName.TEXT_ALIGN,
+                TextAlign.LEFT
+        );
+
+        final SpreadsheetCell cell = SpreadsheetSelection.A1.setFormula(SpreadsheetFormula.EMPTY)
+                .setStyle(style);
+        this.applyAndCheck(
+                Lists.empty(),
+                new FakeSpreadsheetExpressionEvaluationContext() {
+                    @Override
+                    public Optional<SpreadsheetCell> cell() {
+                        return Optional.of(cell);
+                    }
+
+                    @Override
+                    public String toString() {
+                        return "cell: " + this.cell();
+                    }
+                },
+                style
+        );
+    }
+
+    @Override
+    public SpreadsheetExpressionFunctionObjectCellStyle createBiFunction() {
+        return SpreadsheetExpressionFunctionObjectCellStyle.INSTANCE;
+    }
+
+    @Override
+    public int minimumParameterCount() {
+        return 0;
+    }
+
+    // toString.........................................................................................................
+
+    @Test
+    public void testToString() {
+        this.toStringAndCheck(
+                this.createBiFunction(),
+                "cellStyle"
+        );
+    }
+
+    // class............................................................................................................
+
+    @Override
+    public Class<SpreadsheetExpressionFunctionObjectCellStyle> type() {
+        return SpreadsheetExpressionFunctionObjectCellStyle.class;
+    }
+}