Add 'src/be/nikiroo/utils/' from commit '46add0670fdee4bd936a13fe2448c5e20a7ffd0a'
[fanfix.git] / src / be / nikiroo / utils / ui / WrapLayout.java
diff --git a/src/be/nikiroo/utils/ui/WrapLayout.java b/src/be/nikiroo/utils/ui/WrapLayout.java
new file mode 100644 (file)
index 0000000..7f34d79
--- /dev/null
@@ -0,0 +1,205 @@
+package be.nikiroo.utils.ui;
+
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.Dimension;
+import java.awt.FlowLayout;
+import java.awt.Insets;
+
+import javax.swing.JScrollPane;
+import javax.swing.SwingUtilities;
+
+/**
+ * FlowLayout subclass that fully supports wrapping of components.
+ * 
+ * @author https://tips4java.wordpress.com/2008/11/06/wrap-layout/
+ */
+public class WrapLayout extends FlowLayout {
+       private static final long serialVersionUID = 1L;
+
+       /**
+        * Constructs a new <code>WrapLayout</code> with a left alignment and a
+        * default 5-unit horizontal and vertical gap.
+        */
+       public WrapLayout() {
+               super();
+       }
+
+       /**
+        * Constructs a new <code>FlowLayout</code> with the specified alignment and
+        * a default 5-unit horizontal and vertical gap. The value of the alignment
+        * argument must be one of <code>WrapLayout</code>, <code>WrapLayout</code>,
+        * or <code>WrapLayout</code>.
+        * 
+        * @param align
+        *            the alignment value
+        */
+       public WrapLayout(int align) {
+               super(align);
+       }
+
+       /**
+        * Creates a new flow layout manager with the indicated alignment and the
+        * indicated horizontal and vertical gaps.
+        * <p>
+        * The value of the alignment argument must be one of
+        * <code>WrapLayout</code>, <code>WrapLayout</code>, or
+        * <code>WrapLayout</code>.
+        * 
+        * @param align
+        *            the alignment value
+        * @param hgap
+        *            the horizontal gap between components
+        * @param vgap
+        *            the vertical gap between components
+        */
+       public WrapLayout(int align, int hgap, int vgap) {
+               super(align, hgap, vgap);
+       }
+
+       /**
+        * Returns the preferred dimensions for this layout given the <i>visible</i>
+        * components in the specified target container.
+        * 
+        * @param target
+        *            the component which needs to be laid out
+        * @return the preferred dimensions to lay out the subcomponents of the
+        *         specified container
+        */
+       @Override
+       public Dimension preferredLayoutSize(Container target) {
+               return layoutSize(target, true);
+       }
+
+       /**
+        * Returns the minimum dimensions needed to layout the <i>visible</i>
+        * components contained in the specified target container.
+        * 
+        * @param target
+        *            the component which needs to be laid out
+        * @return the minimum dimensions to lay out the subcomponents of the
+        *         specified container
+        */
+       @Override
+       public Dimension minimumLayoutSize(Container target) {
+               Dimension minimum = layoutSize(target, false);
+               minimum.width -= (getHgap() + 1);
+               return minimum;
+       }
+
+       /**
+        * Returns the minimum or preferred dimension needed to layout the target
+        * container.
+        *
+        * @param target
+        *            target to get layout size for
+        * @param preferred
+        *            should preferred size be calculated
+        * @return the dimension to layout the target container
+        */
+       private Dimension layoutSize(Container target, boolean preferred) {
+               synchronized (target.getTreeLock()) {
+                       // Each row must fit with the width allocated to the containter.
+                       // When the container width = 0, the preferred width of the
+                       // container
+                       // has not yet been calculated so lets ask for the maximum.
+
+                       int targetWidth = target.getSize().width;
+                       Container container = target;
+
+                       while (container.getSize().width == 0
+                                       && container.getParent() != null) {
+                               container = container.getParent();
+                       }
+
+                       targetWidth = container.getSize().width;
+
+                       if (targetWidth == 0)
+                               targetWidth = Integer.MAX_VALUE;
+
+                       int hgap = getHgap();
+                       int vgap = getVgap();
+                       Insets insets = target.getInsets();
+                       int horizontalInsetsAndGap = insets.left + insets.right
+                                       + (hgap * 2);
+                       int maxWidth = targetWidth - horizontalInsetsAndGap;
+
+                       // Fit components into the allowed width
+
+                       Dimension dim = new Dimension(0, 0);
+                       int rowWidth = 0;
+                       int rowHeight = 0;
+
+                       int nmembers = target.getComponentCount();
+
+                       for (int i = 0; i < nmembers; i++) {
+                               Component m = target.getComponent(i);
+
+                               if (m.isVisible()) {
+                                       Dimension d = preferred ? m.getPreferredSize() : m
+                                                       .getMinimumSize();
+
+                                       // Can't add the component to current row. Start a new
+                                       // row.
+
+                                       if (rowWidth + d.width > maxWidth) {
+                                               addRow(dim, rowWidth, rowHeight);
+                                               rowWidth = 0;
+                                               rowHeight = 0;
+                                       }
+
+                                       // Add a horizontal gap for all components after the
+                                       // first
+
+                                       if (rowWidth != 0) {
+                                               rowWidth += hgap;
+                                       }
+
+                                       rowWidth += d.width;
+                                       rowHeight = Math.max(rowHeight, d.height);
+                               }
+                       }
+
+                       addRow(dim, rowWidth, rowHeight);
+
+                       dim.width += horizontalInsetsAndGap;
+                       dim.height += insets.top + insets.bottom + vgap * 2;
+
+                       // When using a scroll pane or the DecoratedLookAndFeel we need
+                       // to
+                       // make sure the preferred size is less than the size of the
+                       // target containter so shrinking the container size works
+                       // correctly. Removing the horizontal gap is an easy way to do
+                       // this.
+
+                       Container scrollPane = SwingUtilities.getAncestorOfClass(
+                                       JScrollPane.class, target);
+
+                       if (scrollPane != null && target.isValid()) {
+                               dim.width -= (hgap + 1);
+                       }
+
+                       return dim;
+               }
+       }
+
+       /*
+        * A new row has been completed. Use the dimensions of this row to update
+        * the preferred size for the container.
+        * 
+        * @param dim update the width and height when appropriate
+        * 
+        * @param rowWidth the width of the row to add
+        * 
+        * @param rowHeight the height of the row to add
+        */
+       private void addRow(Dimension dim, int rowWidth, int rowHeight) {
+               dim.width = Math.max(dim.width, rowWidth);
+
+               if (dim.height > 0) {
+                       dim.height += getVgap();
+               }
+
+               dim.height += rowHeight;
+       }
+}
\ No newline at end of file