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support library for libGDX
/** Copyright 2014 Robin Stumm ([email protected], http://dermetfan.net)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License. */
package net.dermetfan.gdx.scenes.scene2d.ui;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer.ShapeType;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.ui.WidgetGroup;
import com.badlogic.gdx.scenes.scene2d.utils.DragListener;
import com.badlogic.gdx.scenes.scene2d.utils.Layout;
import com.badlogic.gdx.utils.SnapshotArray;
import net.dermetfan.gdx.scenes.scene2d.ui.CircularGroup.Modifier.Adapter;
import static net.dermetfan.utils.math.MathUtils.approachZero;
/** a group that aligns its children in a circle
* @author dermetfan
* @since 0.5.0 */
public class CircularGroup extends WidgetGroup {
/** The max angle of all children (in degrees). Default is 360. */
private float fullAngle = 360;
/** The angle added to each child's angle (in degrees). Default is 0. */
private float angleOffset;
/** The smallest {@link #angleOffset} allowed. Default is 0. */
private float minAngleOffset;
/** The greatest {@link #angleOffset} allowed. Default is {@link #fullAngle}. */
private float maxAngleOffset = fullAngle;
/** If an additional, not existent child should be considered in the angle calculation for each child.
* Since {@link #fullAngle} describes the min and max angle for children of this group, two children will overlap at 360 degrees (because 360 degrees mean the min and max angle coincide).
* In this case it would make sense to enable the virtual child. It will reserve the angle needed for one child and therefore overlap with another child at the min/max angle instead of two actual children overlapping.
* Default is true, as appropriate for the default of {@link #fullAngle}. */
private boolean virtualChildEnabled = true;
/** allows advanced modification of each child's angle */
private Modifier modifier;
/** whether children shall be shrinked by the difference between preferred and actual size if the actual size is smaller */
private boolean shrinkChildren = true;
/** the DragManager used to make this group rotatable by dragging and to apply velocity */
private final DragManager dragManager = new DragManager();
/** the current min size (used internally) */
private float cachedMinWidth, cachedMinHeight;
/** the current pref size (used internally) */
private float cachedPrefWidth, cachedPrefHeight;
/** if the current size has to be {@link #computeSize() computed} (used internally) */
private boolean sizeInvalid = true;
/** for internal use */
private final Vector2 tmp = new Vector2();
/** @see #CircularGroup(Modifier) */
public CircularGroup() {
this(null);
}
/** @param modifier the {@link #modifier} to set */
public CircularGroup(Modifier modifier) {
this.modifier = modifier != null ? modifier : new Adapter();
}
/** @see #CircularGroup(Modifier, boolean) */
public CircularGroup(boolean draggable) {
this(null, draggable);
}
/** @param draggable see {@link #setDraggable(boolean)}
* @see #CircularGroup(Modifier) */
public CircularGroup(Modifier modifier, boolean draggable) {
this(modifier);
setDraggable(draggable);
}
@Override
public void act(float delta) {
dragManager.act(delta);
super.act(delta);
}
@Override
public void drawDebug(ShapeRenderer shapes) {
super.drawDebug(shapes);
shapes.set(ShapeType.Line);
shapes.setColor(Color.CYAN);
shapes.ellipse(getX(), getY(), getWidth() * getScaleX(), getHeight() * getScaleY());
SnapshotArray children = getChildren();
for(int index = 0; index < children.size; index++) {
Actor child = children.get(index);
tmp.set(modifier.localAnchor(tmp.set(child.getWidth(), child.getHeight() / 2), child, index, children.size, this));
shapes.line(getX() + getWidth() / 2 * getScaleX(), getY() + getHeight() / 2 * getScaleY(), getX() + (child.getX() + tmp.x) * getScaleX(), getY() + (child.getY() + tmp.y) * getScaleY());
}
}
/** computes {@link #cachedMinWidth}, {@link #cachedMinHeight}, {@link #cachedPrefWidth} and {@link #cachedPrefHeight} */
protected void computeSize() {
cachedMinWidth = cachedMinHeight = Float.POSITIVE_INFINITY;
cachedPrefWidth = cachedPrefHeight = 0;
SnapshotArray children = getChildren();
for(int index = 0; index < children.size; index++) {
Actor child = children.get(index);
// find child size
float minWidth, minHeight, prefWidth, prefHeight;
if(child instanceof Layout) {
Layout layout = (Layout) child;
minWidth = layout.getMinWidth();
minHeight = layout.getMinHeight();
prefWidth = layout.getPrefWidth();
prefHeight = layout.getPrefHeight();
} else {
minWidth = prefWidth = child.getWidth();
minHeight = prefHeight = child.getHeight();
}
// anchor offset and local anchor
tmp.set(modifier.anchorOffset(tmp.setZero(), child, index, children.size, this));
float offsetX = tmp.x, offsetY = tmp.y;
tmp.set(modifier.localAnchor(tmp.set(minWidth, minHeight / 2), child, index, children.size, this)).sub(offsetX, offsetY);
if(tmp.x < minWidth || tmp.x < 0)
minWidth -= tmp.x;
else
minWidth += tmp.x - minWidth;
if(tmp.y < minHeight || tmp.y < 0)
minHeight -= tmp.y;
else
minHeight += tmp.y - minHeight;
tmp.set(modifier.localAnchor(tmp.set(prefWidth, prefHeight / 2), child, index, children.size, this)).sub(offsetX, offsetY);
if(tmp.x < prefWidth || tmp.x < 0)
prefWidth -= tmp.x;
else
prefWidth += tmp.x - prefWidth;
if(tmp.y < prefHeight || tmp.y < 0)
prefHeight -= tmp.y;
else
prefHeight += tmp.y - prefHeight;
// update caches
if(minWidth < cachedMinWidth)
cachedMinWidth = minWidth;
if(minHeight < cachedMinHeight)
cachedMinHeight = minHeight;
if(prefWidth > cachedPrefWidth)
cachedPrefWidth = prefWidth;
if(prefHeight > cachedPrefHeight)
cachedPrefHeight = prefHeight;
}
cachedMinWidth *= 2;
cachedMinHeight *= 2;
cachedPrefWidth *= 2;
cachedPrefHeight *= 2;
// ensure circle
cachedMinWidth = cachedMinHeight = Math.max(cachedMinWidth, cachedMinHeight);
cachedPrefWidth = cachedPrefHeight = Math.max(cachedPrefWidth, cachedPrefHeight);
sizeInvalid = false;
}
/** does not take rotation into account */
@Override
public float getMinWidth() {
if(sizeInvalid)
computeSize();
return cachedMinWidth;
}
/** does not take rotation into account */
@Override
public float getMinHeight() {
if(sizeInvalid)
computeSize();
return cachedMinHeight;
}
@Override
public float getPrefWidth() {
if(sizeInvalid)
computeSize();
return cachedPrefWidth;
}
@Override
public float getPrefHeight() {
if(sizeInvalid)
computeSize();
return cachedPrefHeight;
}
@Override
public void invalidate() {
super.invalidate();
sizeInvalid = true;
}
@Override
public void layout() {
float prefWidthUnderflow = shrinkChildren ? Math.max(0, getPrefWidth() - getWidth()) / 2 : 0, prefHeightUnderflow = shrinkChildren ? Math.max(0, getPrefHeight() - getHeight()) / 2 : 0;
SnapshotArray children = getChildren();
for(int index = 0; index < children.size; index++) {
Actor child = children.get(index);
// get dimensions and resize
float width, height;
if(child instanceof Layout) {
Layout childLayout = (Layout) child;
width = childLayout.getPrefWidth() - prefWidthUnderflow;
width = Math.max(width, childLayout.getMinWidth());
if(childLayout.getMaxWidth() != 0)
width = Math.min(width, childLayout.getMaxWidth());
height = childLayout.getPrefHeight() - prefHeightUnderflow;
height = Math.max(height, childLayout.getMinHeight());
if(childLayout.getMaxHeight() != 0)
height = Math.min(height, childLayout.getMaxHeight());
child.setSize(width, height);
childLayout.validate();
} else {
width = child.getWidth();
height = child.getHeight();
}
float angle = fullAngle / (children.size - (virtualChildEnabled ? 0 : 1)) * index;
angle += angleOffset;
angle = modifier.angle(angle, child, index, children.size, this);
float rotation = modifier.rotation(angle, child, index, children.size, this);
tmp.set(modifier.anchorOffset(tmp.setZero(), child, index, children.size, this));
tmp.rotate(angle);
float offsetX = tmp.x, offsetY = tmp.y;
tmp.set(modifier.localAnchor(tmp.set(width, height / 2), child, index, children.size, this));
float localAnchorX = tmp.x, localAnchorY = tmp.y;
child.setOrigin(localAnchorX, localAnchorY);
child.setRotation(rotation);
child.setPosition(getWidth() / 2 + offsetX - localAnchorX, getHeight() / 2 + offsetY - localAnchorY);
}
}
/** @return if this group is rotatable by dragging with the pointer */
public boolean isDraggable() {
return dragManager.isDraggingActivated();
}
/** @param draggable if this group should be rotatable by dragging with the pointer */
public void setDraggable(boolean draggable) {
dragManager.setDraggingActivated(draggable);
// add/remove dragManager for performance
if(draggable)
addListener(dragManager);
else
removeListener(dragManager);
}
/** @param amount the amount by which to translate {@link #minAngleOffset} and {@link #maxAngleOffset} */
public void translateAngleOffsetLimits(float amount) {
setMinAngleOffset(minAngleOffset + amount);
setMaxAngleOffset(maxAngleOffset + amount);
}
// getters and setters
/** @return the {@link #fullAngle} */
public float getFullAngle() {
return fullAngle;
}
/** {@link #setFullAngle(float, boolean)} with automatic estimation if a {@link #virtualChildEnabled} would make sense.
* @param fullAngle the {@link #fullAngle} to set
* @see #setFullAngle(float, boolean) */
public void setFullAngle(float fullAngle) {
setFullAngle(fullAngle, fullAngle >= 360);
}
/** @param fullAngle the {@link #fullAngle} to set
* @param virtualChildEnabled the {@link #virtualChildEnabled} to set */
public void setFullAngle(float fullAngle, boolean virtualChildEnabled) {
this.fullAngle = fullAngle;
this.virtualChildEnabled = virtualChildEnabled;
invalidate();
}
/** @return the {@link #angleOffset} */
public float getAngleOffset() {
return angleOffset;
}
/** @param angleOffset The {@link #angleOffset} to set. Will be clamped to {@link #minAngleOffset} and {@link #maxAngleOffset}. */
public void setAngleOffset(float angleOffset) {
this.angleOffset = MathUtils.clamp(angleOffset, minAngleOffset, maxAngleOffset);
invalidate();
}
/** @return the {@link #minAngleOffset} */
public float getMinAngleOffset() {
return minAngleOffset;
}
/** clamps {@link #angleOffset} to the new bounds
* @param minAngleOffset the {@link #minAngleOffset} to set */
public void setMinAngleOffset(float minAngleOffset) {
if(minAngleOffset > maxAngleOffset)
throw new IllegalArgumentException("minAngleOffset must not be > maxAngleOffset");
this.minAngleOffset = minAngleOffset;
angleOffset = Math.max(minAngleOffset, angleOffset);
}
/** @return the {@link #maxAngleOffset} */
public float getMaxAngleOffset() {
return maxAngleOffset;
}
/** clamps {@link #angleOffset} to the new bounds
* @param maxAngleOffset the {@link #maxAngleOffset} to set */
public void setMaxAngleOffset(float maxAngleOffset) {
if(maxAngleOffset < minAngleOffset)
throw new IllegalArgumentException("maxAngleOffset must not be < minAngleOffset");
this.maxAngleOffset = maxAngleOffset;
angleOffset = Math.min(angleOffset, maxAngleOffset);
}
/** @return the {@link #virtualChildEnabled} */
public boolean isVirtualChildEnabled() {
return virtualChildEnabled;
}
/** @param virtualChildEnabled the {@link #virtualChildEnabled} to set */
public void setVirtualChildEnabled(boolean virtualChildEnabled) {
this.virtualChildEnabled = virtualChildEnabled;
}
/** @return the {@link #modifier} */
public Modifier getModifier() {
return modifier;
}
/** @param modifier the {@link #modifier} to set */
public void setModifier(Modifier modifier) {
if(modifier == null)
throw new IllegalArgumentException("modifier must not be null");
this.modifier = modifier;
invalidateHierarchy();
}
/** @return the {@link #shrinkChildren} */
public boolean isShrinkChildren() {
return shrinkChildren;
}
/** @param shrinkChildren the {@link #shrinkChildren} to set */
public void setShrinkChildren(boolean shrinkChildren) {
this.shrinkChildren = shrinkChildren;
}
/** @return the {@link #dragManager} */
public DragManager getDragManager() {
return dragManager;
}
/** @author dermetfan
* @since 0.5.0
* @see #modifier */
public interface Modifier {
/** @param defaultAngle the linearly calculated angle of the child for even distribution
* @return the angle of the child ({@link #angleOffset} will be added to this) */
float angle(float defaultAngle, Actor child, int index, int numChildren, CircularGroup group);
/** @param angle the angle of the child (from {@link #angle(float, Actor, int, int, CircularGroup)})
* @return the rotation of the child */
float rotation(float angle, Actor child, int index, int numChildren, CircularGroup group);
/** @param anchorOffset the default anchor offset ({@code [0:0]})
* @return the anchor offset of the child, relative to the group center */
Vector2 anchorOffset(Vector2 anchorOffset, Actor child, int index, int numChildren, CircularGroup group);
/** @param localAnchor the default local anchorOffset ({@code [childWidth:childHeight / 2]})
* @return the local anchorOffset of the child, relative to the child itself */
Vector2 localAnchor(Vector2 localAnchor, Actor child, int index, int numChildren, CircularGroup group);
/** Use this if you only want to override some of {@link Modifier}'s methods.
* All method implementations return the default value.
* @author dermetfan
* @since 0.5.0 */
public static class Adapter implements Modifier {
@Override
public float angle(float defaultAngle, Actor child, int index, int numChildren, CircularGroup group) {
return defaultAngle;
}
@Override
public float rotation(float angle, Actor child, int index, int numChildren, CircularGroup group) {
return angle;
}
@Override
public Vector2 anchorOffset(Vector2 anchorOffset, Actor child, int index, int numChildren, CircularGroup group) {
return anchorOffset;
}
@Override
public Vector2 localAnchor(Vector2 localAnchor, Actor child, int index, int numChildren, CircularGroup group) {
return localAnchor;
}
}
}
/** manages dragging and velocity of its enclosing CircularGroup instance
* @author dermetfan
* @since 0.5.0 */
public class DragManager extends DragListener {
/** if the velocity should be applied */
private boolean velocityActivated = true;
/** if dragging should be possible */
private boolean draggingActivated = true;
/** the velocity of the rotation */
private float velocity;
/** the deceleration applied to {@link #velocity} */
private float deceleration = 500;
/** if this group is currently being dragged (internal use) */
private boolean dragging;
/** the previous angle for delta calculation (internal use) */
private float previousAngle;
/** The greatest absolute delta value allowed. Needed to avoid glitches. */
private float maxAbsDelta = 350;
/** inner class singleton */
private DragManager() {}
@Override
public void dragStart(InputEvent event, float x, float y, int pointer) {
if(!draggingActivated)
return;
velocity = 0;
dragging = true;
previousAngle = angle(x, y);
}
@Override
public void drag(InputEvent event, float x, float y, int pointer) {
if(!draggingActivated)
return;
float currentAngle = angle(x, y);
float delta = currentAngle - previousAngle;
previousAngle = currentAngle;
if(Math.abs(delta) > maxAbsDelta)
return;
velocity = delta * Gdx.graphics.getFramesPerSecond();
float newAngleOffset = angleOffset + delta;
float oldAngleOffset = angleOffset;
setAngleOffset(newAngleOffset);
if(angleOffset != oldAngleOffset)
invalidate();
}
@Override
public void dragStop(InputEvent event, float x, float y, int pointer) {
if(!draggingActivated)
return;
dragging = false;
}
/** changes {@link #angleOffset} according to {@link #velocity} and reduces {@link #velocity} according to {@link #deceleration}
* @param delta see {@link com.badlogic.gdx.Graphics#getDeltaTime()} */
public void act(float delta) {
if(dragging || velocity == 0 || !velocityActivated)
return;
setAngleOffset(angleOffset + velocity * delta);
invalidate();
if(deceleration == 0)
return;
velocity = approachZero(velocity, deceleration * delta);
}
/** @return the angle of the given x and y to the center of the group */
private float angle(float x, float y) {
return tmp.set(x, y).sub(getWidth() / 2, getHeight() / 2).angle();
}
/** @param angleOffset the {@link #angleOffset} to set so that if {@link #minAngleOffset} and {@link #maxAngleOffset} coincide on 360 degrees it doesn't get clamped */
private void setAngleOffset(float angleOffset) {
if(maxAngleOffset - minAngleOffset == 360)
CircularGroup.this.angleOffset = net.dermetfan.utils.math.MathUtils.normalize(angleOffset, minAngleOffset, maxAngleOffset);
else
CircularGroup.this.setAngleOffset(angleOffset);
}
// getters and setters
/** @return the {@link #velocityActivated} */
public boolean isVelocityActivated() {
return velocityActivated;
}
/** @param velocityActivated the {@link #velocityActivated} to set */
public void setVelocityActivated(boolean velocityActivated) {
this.velocityActivated = velocityActivated;
}
/** @return the {@link #draggingActivated} */
public boolean isDraggingActivated() {
return draggingActivated;
}
/** @param draggingActivated the {@link #draggingActivated} to set */
public void setDraggingActivated(boolean draggingActivated) {
this.draggingActivated = draggingActivated;
}
/** @return the {@link #velocity} */
public float getVelocity() {
return velocity;
}
/** @param velocity the {@link #velocity} to set */
public void setVelocity(float velocity) {
this.velocity = velocity;
}
/** @return the {@link #deceleration} */
public float getDeceleration() {
return deceleration;
}
/** @param deceleration the {@link #deceleration} to set */
public void setDeceleration(float deceleration) {
this.deceleration = deceleration;
}
/** @return the {@link #maxAbsDelta} */
public float getMaxAbsDelta() {
return maxAbsDelta;
}
/** @param maxAbsDelta the {@link #maxAbsDelta} to set */
public void setMaxAbsDelta(float maxAbsDelta) {
this.maxAbsDelta = maxAbsDelta;
}
}
}