WListPanel: Split margin into insets and gaps

Resolves #221.

3 files changed, 202 insertions, 5 deletions

diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WListPanel.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WListPanel.java
index d36fb70..5a4c35b 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WListPanel.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WListPanel.java
@@ -7,10 +7,13 @@ import net.minecraft.client.gui.DrawContext;
 import io.github.cottonmc.cotton.gui.GuiDescription;
 import io.github.cottonmc.cotton.gui.widget.data.Axis;
 import io.github.cottonmc.cotton.gui.widget.data.InputResult;
+import io.github.cottonmc.cotton.gui.widget.data.Insets;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.BiConsumer;
 import java.util.function.Supplier;
 
@@ -51,8 +54,16 @@ public class WListPanel<D, W extends WWidget> extends WClippedPanel {
 	 */
 	protected boolean fixedHeight = false;
 
+	/**
+	 * @deprecated Replaced with {@link #getInsets() insets} and {@link #getGap() gap}.
+	 */
+	@Deprecated(forRemoval = true)
 	protected int margin = 4;
 
+	// When the margin field is removed, these should get default values Insets(4, 4) and 4.
+	private @Nullable Insets insets = null;
+	private int gap = -1;
+
 	/**
 	 * The scroll bar of this list.
 	 */
@@ -153,8 +164,10 @@ public class WListPanel<D, W extends WWidget> extends WClippedPanel {
 		}
 		if (cellHeight<4) cellHeight=4;
 
-		int layoutHeight = this.getHeight()-(margin*2);
-		int cellsHigh = Math.max((layoutHeight+margin) / (cellHeight + margin), 1); // At least one cell is always visible
+		Insets insets = getInsets();
+		int gap = getGap();
+		int layoutHeight = this.getHeight() - insets.top() - insets.bottom();
+		int cellsHigh = Math.max((layoutHeight + gap) / (cellHeight + gap), 1); // At least one cell is always visible
 
 		//System.out.println("Adding children...");
 
@@ -190,10 +203,10 @@ public class WListPanel<D, W extends WWidget> extends WClippedPanel {
 
 				//At this point, w is nonnull and configured by d
 				if (w.canResize()) {
-					w.setSize(this.width-(margin*2) - scrollBar.getWidth(), cellHeight);
+					w.setSize(this.width - insets.left() - insets.right() - scrollBar.getWidth(), cellHeight);
 				}
-				w.x = margin;
-				w.y = margin + ((cellHeight+margin) * i);
+				w.x = insets.left();
+				w.y = insets.top() + ((cellHeight + gap) * i);
 				this.children.add(w);
 			}
 		}
@@ -227,4 +240,50 @@ public class WListPanel<D, W extends WWidget> extends WClippedPanel {
 	public WScrollBar getScrollBar() {
 		return scrollBar;
 	}
+
+	/**
+	 * {@return the layout insets used for the contents of this list}
+	 * @since 9.1.0
+	 */
+	public Insets getInsets() {
+		// Returns the *effective* insets of this list for backwards compat.
+		return insets != null ? insets : new Insets(margin, margin);
+	}
+
+	/**
+	 * Sets the layout insets used for the contents of this list.
+	 *
+	 * @param insets the layout insets
+	 * @return this list
+	 * @since 9.1.0
+     */
+	public WListPanel<D, W> setInsets(Insets insets) {
+		this.insets = Objects.requireNonNull(insets, "Insets cannot be null");
+		return this;
+	}
+
+	/**
+	 * {@return the gap between list items}
+	 * @since 9.1.0
+	 */
+	public int getGap() {
+		// Returns the *effective* gap of this list for backwards compat.
+		return gap >= 0 ? gap : margin;
+	}
+
+	/**
+	 * Sets the gap between list items.
+	 *
+	 * @param gap the gap, must be non-negative
+	 * @return this list
+	 * @since 9.1.0
+	 */
+	public WListPanel<D, W> setGap(int gap) {
+		if (gap < 0) {
+			throw new IllegalArgumentException("Gap cannot be negative (was " + gap + ")");
+		}
+
+		this.gap = gap;
+		return this;
+	}
 }
diff --git a/src/testMod/java/io/github/cottonmc/test/client/LibGuiTestClient.java b/src/testMod/java/io/github/cottonmc/test/client/LibGuiTestClient.java
index 8d44715..aef04ed 100644
--- a/src/testMod/java/io/github/cottonmc/test/client/LibGuiTestClient.java
+++ b/src/testMod/java/io/github/cottonmc/test/client/LibGuiTestClient.java
@@ -70,6 +70,7 @@ public class LibGuiTestClient implements ClientModInitializer {
 						.then(literal("titlealignment").executes(openScreen(Text.literal("test title"), client -> new TitleAlignmentTestGui())))
 						.then(literal("texture").executes(openScreen(client -> new TextureTestGui())))
 						.then(literal("textalignment").executes(openScreen(client -> new TextAlignmentTestGui())))
+						.then(literal("list").executes(openScreen(client -> new ListTestGui())))
 		));
 	}
 
diff --git a/src/testMod/java/io/github/cottonmc/test/client/ListTestGui.java b/src/testMod/java/io/github/cottonmc/test/client/ListTestGui.java
new file mode 100644
index 0000000..42eb8b5
--- /dev/null
+++ b/src/testMod/java/io/github/cottonmc/test/client/ListTestGui.java
@@ -0,0 +1,137 @@
+package io.github.cottonmc.test.client;
+
+import net.minecraft.text.Text;
+import net.minecraft.util.Formatting;
+
+import io.github.cottonmc.cotton.gui.client.BackgroundPainter;
+import io.github.cottonmc.cotton.gui.client.LightweightGuiDescription;
+import io.github.cottonmc.cotton.gui.widget.WGridPanel;
+import io.github.cottonmc.cotton.gui.widget.WLabel;
+import io.github.cottonmc.cotton.gui.widget.WLabeledSlider;
+import io.github.cottonmc.cotton.gui.widget.WListPanel;
+import io.github.cottonmc.cotton.gui.widget.data.Axis;
+import io.github.cottonmc.cotton.gui.widget.data.Insets;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+
+public class ListTestGui extends LightweightGuiDescription {
+	private static final String[] LOREM = {
+			"Eius",
+			"architecto",
+			"dolores",
+			"in",
+			"delectus",
+			"omnis",
+			"Exercitationem",
+			"fugit",
+			"dolorem",
+			"sapiente",
+			"impedit",
+			"Occaecati",
+			"consequatur",
+			"omnis",
+			"nam",
+			"eveniet",
+			"eius",
+			"Eos",
+			"quasi",
+			"numquam",
+			"placeat",
+			"eaque",
+			"sapiente",
+			"Dolorum",
+			"magnam",
+			"eius",
+			"labore",
+			"voluptatem",
+			"est",
+			"voluptatem",
+			"aut",
+			"qui"
+	};
+
+	public ListTestGui() {
+		WGridPanel root = (WGridPanel) rootPanel;
+
+		List<Formatting> formattings = Arrays.stream(Formatting.values())
+				.filter(Formatting::isColor)
+				.toList();
+		Random random = new Random();
+		List<Text> data = Arrays.stream(LOREM)
+				.<Text>map(s -> {
+					Formatting formatting = formattings.get(random.nextInt(formattings.size()));
+					return Text.literal(s).formatted(formatting, Formatting.BOLD);
+				})
+				.toList();
+
+		WListPanel<Text, WLorem> listPanel = new WListPanel<>(data, WLorem::new, (text, widget) -> widget.label.setText(text));
+		WLabeledSlider topSlider = new WLabeledSlider(0, 16, Axis.HORIZONTAL, Text.literal("Top insets"));
+		WLabeledSlider bottomSlider = new WLabeledSlider(0, 16, Axis.HORIZONTAL, Text.literal("Bottom insets"));
+		WLabeledSlider leftSlider = new WLabeledSlider(0, 16, Axis.HORIZONTAL, Text.literal("Left insets"));
+		WLabeledSlider rightSlider = new WLabeledSlider(0, 16, Axis.HORIZONTAL, Text.literal("Right insets"));
+		WLabeledSlider gapSlider = new WLabeledSlider(0, 16, Axis.VERTICAL, Text.literal("Gap"));
+
+		topSlider.setValue(listPanel.getInsets().top());
+		topSlider.setValueChangeListener(top -> {
+			Insets insets = listPanel.getInsets();
+			Insets newInsets = new Insets(top, insets.left(), insets.bottom(), insets.right());
+			listPanel.setInsets(newInsets);
+			listPanel.layout();
+		});
+
+		bottomSlider.setValue(listPanel.getInsets().bottom());
+		bottomSlider.setValueChangeListener(bottom -> {
+			Insets insets = listPanel.getInsets();
+			Insets newInsets = new Insets(insets.top(), insets.left(), bottom, insets.right());
+			listPanel.setInsets(newInsets);
+			listPanel.layout();
+		});
+
+		leftSlider.setValue(listPanel.getInsets().left());
+		leftSlider.setValueChangeListener(left -> {
+			Insets insets = listPanel.getInsets();
+			Insets newInsets = new Insets(insets.top(), left, insets.bottom(), insets.right());
+			listPanel.setInsets(newInsets);
+			listPanel.layout();
+		});
+
+		rightSlider.setValue(listPanel.getInsets().right());
+		rightSlider.setValueChangeListener(right -> {
+			Insets insets = listPanel.getInsets();
+			Insets newInsets = new Insets(insets.top(), insets.left(), insets.bottom(), right);
+			listPanel.setInsets(newInsets);
+			listPanel.layout();
+		});
+
+		gapSlider.setValue(listPanel.getGap());
+		gapSlider.setValueChangeListener(gap -> {
+			listPanel.setGap(gap);
+			listPanel.layout();
+		});
+
+		root.setGaps(2, 2);
+		root.add(topSlider, 0, 0, 3, 1);
+		root.add(bottomSlider, 3, 0, 3, 1);
+		root.add(leftSlider, 0, 1, 3, 1);
+		root.add(rightSlider, 3, 1, 3, 1);
+		root.add(gapSlider, 6, 0, 1, 2);
+		root.add(listPanel, 0, 2, 6, 6);
+		root.validate(this);
+	}
+
+	private static class WLorem extends WGridPanel {
+		private final WLabel label = new WLabel(Text.empty());
+
+		private WLorem() {
+			setInsets(Insets.ROOT_PANEL);
+			add(label, 0, 0);
+		}
+
+		@Override
+		public void addPainters() {
+			setBackgroundPainter(BackgroundPainter.VANILLA);
+		}
+	}
+}