dev.robocode.tankroyale.gui.ui.components.WrapLayout.kt Maven / Gradle / Ivy
package dev.robocode.tankroyale.gui.ui.components
import java.awt.Container
import java.awt.Dimension
import java.awt.FlowLayout
import javax.swing.JScrollPane
import javax.swing.SwingUtilities
// From: https://tips4java.wordpress.com/2008/11/06/wrap-layout/
/**
* FlowLayout subclass that fully supports wrapping of components.
*
* Constructs a new `WrapLayout` with a left alignment and a default
* 5-unit horizontal and vertical gap.
*/
class WrapLayout : FlowLayout() {
/**
* Returns the preferred dimensions for this layout given the
* *visible* 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 fun preferredLayoutSize(target: Container): Dimension {
return layoutSize(target, true)
}
/**
* Returns the minimum dimensions needed to layout the *visible*
* 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 fun minimumLayoutSize(target: Container): Dimension {
val minimum = layoutSize(target, false)
minimum.width -= hgap + 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 fun layoutSize(target: Container, preferred: Boolean): Dimension {
synchronized(target.treeLock) {
// Each row must fit with the width allocated to the container.
// When the container width = 0, the preferred width of the container
// has not yet been calculated so lets ask for the maximum.
var container = target
while (container.size.width == 0 && container.parent != null) {
container = container.parent
}
var targetWidth = container.size.width
if (targetWidth == 0) targetWidth = Int.MAX_VALUE
val insets = target.insets
val horizontalInsetsAndGap = insets.left + insets.right + hgap * 2
val maxWidth = targetWidth - horizontalInsetsAndGap
// Fit components into the allowed width
val dim = Dimension(0, 0)
var rowWidth = 0
var rowHeight = 0
val nMembers = target.componentCount
for (i in 0 until nMembers) {
val m = target.getComponent(i)
if (m.isVisible) {
val d = if (preferred) m.preferredSize else m.minimumSize
// 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 = rowHeight.coerceAtLeast(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.
val scrollPane = SwingUtilities.getAncestorOfClass(JScrollPane::class.java, 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 fun addRow(dim: Dimension, rowWidth: Int, rowHeight: Int) {
dim.width = dim.width.coerceAtLeast(rowWidth)
if (dim.height > 0) {
dim.height += vgap
}
dim.height += rowHeight
}
}