Couple of major improvements for Java version.

Including: - Extracting spacing logic into a Spacing class - Fix layout update issue - Add null assertions support
2015-01-19 12:37:30 +00:00
parent d82ec0ddfd
commit e1969bda05
8 changed files with 372 additions and 242 deletions
--- a/src/java/src/com/facebook/csslayout/Spacing.java
+++ b/src/java/src/com/facebook/csslayout/Spacing.java
@@ -0,0 +1,103 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+package com.facebook.csslayout;
+
+/**
+ * Utility class for handling CSS spacing (padding, margin, and borders). This is mostly necessary
+ * to properly implement interactions and updates for properties like margin, marginLeft, and
+ * marginHorizontal. This is not a great API and should probably be updated to use actual objects
+ * for type safety, defaults safety, and simplicity.
+ */
+public class Spacing {
+
+  // Indices into FullSpacingArray and SpacingResultArray
+  public static final int LEFT = 0;
+  public static final int TOP = 1;
+  public static final int RIGHT = 2;
+  public static final int BOTTOM = 3;
+  public static final int VERTICAL = 4;
+  public static final int HORIZONTAL = 5;
+  public static final int ALL = 6;
+
+  /**
+   * @return an instance of an array that can be used with {@link #updateSpacing}. Stores
+   * the value for each spacing type or NaN if it hasn't been explicitly set.
+   */
+  public static float[] newFullSpacingArray() {
+    return new float[] {
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+        CSSConstants.UNDEFINED,
+    };
+  }
+
+  /**
+   * @return {@link #newSpacingResultArray} filled with zero.
+   */
+  public static float[] newSpacingResultArray() {
+    return newSpacingResultArray(0);
+  }
+
+  /**
+   * @return an instance of an array used to store the end result of the interactions between the
+   * values in a full spacing array. Use {@link #TOP}, etc to access result values.
+   */
+  public static float[] newSpacingResultArray(float defaultValue) {
+    return new float[] {
+        defaultValue,
+        defaultValue,
+        defaultValue,
+        defaultValue,
+    };
+  }
+
+  /**
+   * Given the fullSpacing from {@link #newFullSpacingArray()} and the spacingResult from
+   * {@link #newSpacingResultArray()} from a View, update them both to reflect a new value for the
+   * given spacingType (e.g. {@link #TOP}). defaultValue specifies the result value that should be
+   * used whenever a spacing property hasn't been set.
+   */
+  public static void updateSpacing(
+      float[] fullSpacing,
+      float[] spacingResult,
+      int spacingType,
+      float value,
+      float defaultValue) {
+    fullSpacing[spacingType] = value;
+    spacingResult[Spacing.TOP] =
+        !CSSConstants.isUndefined(fullSpacing[Spacing.TOP]) ? fullSpacing[Spacing.TOP]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.VERTICAL]) ?
+                fullSpacing[Spacing.VERTICAL]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.ALL]) ? fullSpacing[Spacing.ALL]
+            : defaultValue;
+    spacingResult[Spacing.BOTTOM] =
+        !CSSConstants.isUndefined(fullSpacing[Spacing.BOTTOM]) ? fullSpacing[Spacing.BOTTOM]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.VERTICAL]) ?
+                fullSpacing[Spacing.VERTICAL]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.ALL]) ? fullSpacing[Spacing.ALL]
+            : defaultValue;
+    spacingResult[Spacing.LEFT] =
+        !CSSConstants.isUndefined(fullSpacing[Spacing.LEFT]) ? fullSpacing[Spacing.LEFT]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.HORIZONTAL]) ?
+                fullSpacing[Spacing.HORIZONTAL]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.ALL]) ? fullSpacing[Spacing.ALL]
+            : defaultValue;
+    spacingResult[Spacing.RIGHT] =
+        !CSSConstants.isUndefined(fullSpacing[Spacing.RIGHT]) ? fullSpacing[Spacing.RIGHT]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.HORIZONTAL]) ?
+                fullSpacing[Spacing.HORIZONTAL]
+            : !CSSConstants.isUndefined(fullSpacing[Spacing.ALL]) ? fullSpacing[Spacing.ALL]
+            : defaultValue;
+  }
+}