JAL-4154 Add Platform.forArch method.

Platform.forArch allows to specify constants that depend on
architecture.

diff --git a/src/jalview/util/Platform.java b/src/jalview/util/Platform.java
index 573e2d5..5f51255 100644 (file)
--- a/src/jalview/util/Platform.java
+++ b/src/jalview/util/Platform.java
@@ -33,6 +33,7 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.net.URL;
+import java.util.Objects;
 import java.util.Properties;
 
 import javax.swing.SwingUtilities;
@@ -138,6 +139,147 @@ public class Platform
   }
 
   /**
+   * Construct the value that depends on the system architecture. The methods
+   * setting the value for subsequent platforms are chained after this call and
+   * finalized with a {@link PlatformDependentValue#value() value()} call.
+   * 
+   * Example: {@code
+   *   Platform.forArch(120).forMac(114).forWin(112).forLinux(115).value();
+   * }
+   * 
+   * @param <T>
+   *          type of the value
+   * @param defaultValue
+   *          default value used if platform not determined
+   * @return platform dependent value wrapper object
+   */
+  public static <T> PlatformDependentValue<T> forArch(T defaultValue)
+  {
+    return new PlatformDependentValue<T>(defaultValue);
+  }
+
+  /**
+   * 
+   * @author mmwarowny
+   *
+   * @param <T>
+   *          type of the value
+   */
+  public static class PlatformDependentValue<T>
+  {
+    private T defaultValue = null;
+
+    private T macValue = null;
+
+    private T winValue = null;
+
+    private T linuxValue = null;
+
+    private T jsValue = null;
+
+    private T headlessValue = null;
+
+    private PlatformDependentValue(T value)
+    {
+      Objects.requireNonNull(value);
+      defaultValue = value;
+    }
+
+    /**
+     * Set the value used on Mac platform.
+     * 
+     * @param value
+     *          parameter value
+     * @return
+     */
+    public PlatformDependentValue<T> forMac(T value)
+    {
+      Objects.requireNonNull(value);
+      macValue = value;
+      return this;
+    }
+
+    /**
+     * Set the value used on Windows platform.
+     * 
+     * @param value
+     *          parameter value
+     * @return
+     */
+    public PlatformDependentValue<T> forWin(T value)
+    {
+      Objects.requireNonNull(value);
+      winValue = value;
+      return this;
+    }
+
+    /**
+     * Set the value used on Linux platform.
+     * 
+     * @param value
+     *          parameter value
+     * @return
+     */
+    public PlatformDependentValue<T> forLinux(T value)
+    {
+      Objects.requireNonNull(value);
+      linuxValue = value;
+      return this;
+    }
+
+    /**
+     * Set the value used on JS platform.
+     * 
+     * @param value
+     *          parameter value
+     * @return
+     */
+    public PlatformDependentValue<T> forJS(T value)
+    {
+      Objects.requireNonNull(value);
+      jsValue = value;
+      return this;
+    }
+
+    /**
+     * Set the value used on headless platform. The headless value takes
+     * precedence over other platforms if set.
+     * 
+     * @param value
+     *          parameter value
+     * @return
+     */
+    public PlatformDependentValue<T> forHeadless(T value)
+    {
+      Objects.requireNonNull(value);
+      headlessValue = value;
+      return this;
+    }
+
+    /**
+     * Get the value of the parameter respecting the platform. The headless
+     * platform takes precedence over any other platform if it has the value
+     * set.
+     * 
+     * @return parameter value depending on the platform
+     */
+    public T value()
+    {
+      if (headlessValue != null && isHeadless())
+        return headlessValue;
+      if (macValue != null && isMac())
+        return macValue;
+      if (winValue != null && isWin())
+        return winValue;
+      if (linuxValue != null && isLinux())
+        return linuxValue;
+      if (jsValue != null && isJS())
+        return jsValue;
+      return defaultValue;
+    }
+  }
+
+  /**
    * 
    * @return nominal maximum command line length for this platform
    */