Renderer/src/main/java/electrosphere/renderer/ui/elements/Button.java

package electrosphere.renderer.ui.elements;

import java.util.LinkedList;
import java.util.List;

import org.joml.Vector3f;

import electrosphere.renderer.ui.ClickableElement;
import electrosphere.renderer.ui.ContainerElement;
import electrosphere.renderer.ui.DrawableElement;
import electrosphere.renderer.ui.Element;
import electrosphere.renderer.ui.FocusableElement;
import electrosphere.renderer.ui.events.ClickEvent;
import electrosphere.renderer.ui.events.Event;
import electrosphere.renderer.ui.events.FocusEvent;
import electrosphere.renderer.ui.events.MouseEvent;

public class Button implements DrawableElement, FocusableElement, ContainerElement, ClickableElement {

    List<Element> childList = new LinkedList<Element>();

    int width = -1;
    int height = -1;
    
    int positionX = -1;
    int positionY = -1;
    
    int parentWidth = 1;
    int parentHeight = 1;
    
    boolean visible = false;
    boolean focused = false;

    FocusEventCallback onFocusCallback;
    FocusEventCallback onLoseFocusCallback;
    ClickEventCallback clickCallback;

    public int getWidth() {
        if(width == -1){
            int minX = -1;
            int maxX = -1;
            for(Element child : childList){
                if(minX == -1){
                    minX = child.getPositionX();
                } else if(child.getPositionX() < minX){
                    minX = child.getPositionX();
                }
                if(maxX == -1){
                    maxX = child.getPositionX() + child.getWidth();
                } else if(child.getPositionX() + child.getWidth() > maxX){
                    maxX = child.getPositionX() + child.getWidth();
                }
            }
            if(minX == -1){
                minX = 0;
            }
            if(maxX == -1){
                maxX = 0;
            }
            return maxX - minX;
        } else {
            return width;
        }
    }

    public int getHeight() {
        if(height == -1){
            int minY = -1;
            int maxY = -1;
            for(Element child : childList){
                if(minY == -1){
                    minY = child.getPositionY();
                } else if(child.getPositionY() < minY){
                    minY = child.getPositionY();
                }
                if(maxY == -1){
                    maxY = child.getPositionY() + child.getHeight();
                } else if(child.getPositionY() + child.getHeight() > maxY){
                    maxY = child.getPositionY() + child.getHeight();
                }
            }
            if(minY == -1){
                minY = 0;
            }
            if(maxY == -1){
                maxY = 0;
            }
            return maxY - minY;
        } else {
            return height;
        }
    }

    public int getPositionX() {
        if(positionX == -1){
            int minX = -1;
            for(Element child : childList){
                if(minX == -1){
                    minX = child.getPositionX();
                } else if(child.getPositionX() < minX){
                    minX = child.getPositionX();
                }
            }
            if(minX == -1){
                minX = 0;
            }
            return minX;
        } else {
            return positionX;
        }
    }

    public int getPositionY() {
        if(positionY == -1){
            int minY = -1;
            for(Element child : childList){
                if(minY == -1){
                    minY = child.getPositionY();
                } else if(child.getPositionY() < minY){
                    minY = child.getPositionY();
                }
            }
            if(minY == -1){
                minY = 0;
            }
            return minY;
        } else {
            return positionY;
        }
    }

    public boolean getVisible() {
        return visible;
    }

    public void setWidth(int width) {
        this.width = width;
    }

    public void setHeight(int height) {
        this.height = height;
    }

    public void setPositionX(int posX) {
        int deltaX = posX - getPositionX();
        this.positionX = posX;
        for(Element child : childList){
            child.setPositionX(child.getPositionX() + deltaX);
        }
    }

    public void setPositionY(int posY) {
        int deltaY = posY - getPositionY();
        this.positionY = posY;
        for(Element child : childList){
            child.setPositionY(child.getPositionY() + deltaY);
        }
    }

    public void setVisible(boolean draw) {
        this.visible = draw;
    }
    
    public void setParentWidth(int width){
        parentWidth = width;
    }
    
    public void setParentHeight(int height){
        this.parentHeight = height;
    }

    @Override
    public boolean isFocused() {
        return focused;
    }

    void onFocus(FocusEvent event) {
        if(onFocusCallback != null){
            onFocusCallback.execute(event);
        } else {
            for(Element child : childList){
                if(child instanceof Label){
                    Label childLabel = (Label) child;
                    childLabel.setColor(new Vector3f(1,0,0));
                }
            }
        }
    }

    void onLoseFocus(FocusEvent event) {
        if(onLoseFocusCallback != null){
            onLoseFocusCallback.execute(event);
        } else {
            for(Element child : childList){
                if(child instanceof Label){
                    Label childLabel = (Label) child;
                    childLabel.setColor(new Vector3f(1,1,1));
                }
            }
        }
    }

    public void draw(int parentFramebufferPointer, int parentWidth, int parentHeight) {
        for(Element child : childList){
            if(child instanceof DrawableElement){
                DrawableElement drawableChild = (DrawableElement) child;
                drawableChild.draw(parentFramebufferPointer,parentWidth,parentHeight);
            }
        }
    }

    @Override
    public void addChild(Element child) {
        childList.add(child);
        if(child instanceof DrawableElement){
            DrawableElement drawableChild = (DrawableElement) child;
            drawableChild.setParentWidth(width);
            drawableChild.setParentHeight(height);
            drawableChild.setVisible(false);
        }
    }

    @Override
    public List<Element> getChildren() {
        return childList;
    }

    @Override
    public void removeChild(Element child) {
        childList.remove(child);
    }

    @Override
    public void setOnFocus(FocusEventCallback callback) {
        onFocusCallback = callback;
    }

    @Override
    public void setOnLoseFocus(FocusEventCallback callback) {
        onLoseFocusCallback = callback;
    }

    @Override
    public void setOnClick(ClickEventCallback callback) {
        clickCallback = callback;
    }

    public boolean handleEvent(Event event){
        if(event instanceof MouseEvent){
            return false;
        }
        if(event instanceof FocusEvent){
            FocusEvent focusEvent = (FocusEvent) event;
            if(focusEvent.isFocused()){
                this.focused = true;
                onFocus(focusEvent);
            } else {
                this.focused = false;
                onLoseFocus(focusEvent);
            }
            return false;
        }
        if(event instanceof ClickEvent){
            if(clickCallback != null){
                clickCallback.execute((ClickEvent)event);
            }
        }
        return true;
    }
    
}