MTU-Dining/app/src/main/java/com/thebrokenrail/mtudining/widget/CategoryView.java

package com.thebrokenrail.mtudining.widget;

import android.content.Context;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.FrameLayout;
import android.widget.LinearLayout;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.widget.AppCompatTextView;

import com.google.android.material.card.MaterialCardView;
import com.thebrokenrail.mtudining.R;
import com.thebrokenrail.mtudining.util.Category;

import java.util.function.Consumer;

/**
 * Widget that shows a category of items.
 */
public class CategoryView extends FrameLayout {
    private final MaterialCardView card;
    private final LinearLayout children;
    private final AppCompatTextView title;

    public CategoryView(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        LinearLayout inner = new LinearLayout(context);
        inner.setOrientation(LinearLayout.VERTICAL);
        addView(inner);

        // Set Margin
        LayoutParams layoutParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
        int margin = getResources().getDimensionPixelSize(R.dimen.margin);
        layoutParams.setMargins(margin, 0, margin, margin);
        inner.setLayoutParams(layoutParams);

        // Add Title
        title = new AppCompatTextView(context);
        TypedValue value = new TypedValue();
        context.getTheme().resolveAttribute(androidx.appcompat.R.attr.colorPrimary, value, true);
        title.setTextColor(value.data);
        title.setTextSize(TypedValue.COMPLEX_UNIT_PX, getResources().getDimension(R.dimen.category_font_size));
        title.setTypeface(null, Typeface.BOLD);
        title.setClickable(true);
        title.setFocusable(true);
        inner.addView(title);
        LinearLayout.LayoutParams innerLayoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        title.setLayoutParams(innerLayoutParams);

        // Setup Card
        card = new MaterialCardView(context, null, com.google.android.material.R.attr.materialCardViewElevatedStyle);
        inner.addView(card);
        innerLayoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        innerLayoutParams.setMargins(0, margin, 0, 0);
        card.setLayoutParams(innerLayoutParams);

        // Setup Children
        children = new LinearLayout(context);
        children.setOrientation(LinearLayout.VERTICAL);
        card.addView(children);
        MaterialCardView.LayoutParams cardLayoutParams = new MaterialCardView.LayoutParams(MaterialCardView.LayoutParams.MATCH_PARENT, MaterialCardView.LayoutParams.WRAP_CONTENT);
        children.setLayoutParams(cardLayoutParams);
    }

    /**
     * Setup widget.
     * @param category The category
     * @param onClickTitle Callback when clicking on title
     * @param onClickItem Callback when clicking on an item
     */
    public <T extends Category.Named> void setup(Category<T> category, Runnable onClickTitle, Consumer<T> onClickItem) {
        String icon = category.isOpen ? "▼" : "▶";
        String titleText = category.name;
        if (getResources().getConfiguration().getLayoutDirection() == LAYOUT_DIRECTION_RTL) {
            // RTL
            titleText += " " + icon;
        } else {
            // LTR
            titleText = icon + " " + titleText;
        }
        title.setText(titleText);
        card.setVisibility(category.isOpen ? VISIBLE : GONE);
        title.setOnClickListener(v -> onClickTitle.run());
        // Add Items
        clearItems();
        for (T item : category.items) {
            addItem(item.getName(), () -> onClickItem.accept(item));
        }
    }

    /**
     * Clear category.
     */
    private void clearItems() {
        children.removeAllViews();
    }

    /**
     * Add item.
     * @param name Item name
     * @param onClick Click handler
     */
    private void addItem(String name, Runnable onClick) {
        AppCompatTextView item = new AppCompatTextView(getContext());
        // Text
        item.setText(name);
        // Text Size
        item.setTextSize(TypedValue.COMPLEX_UNIT_PX, item.getResources().getDimension(R.dimen.item_font_size));
        // Padding
        int margin = getResources().getDimensionPixelSize(R.dimen.margin);
        item.setPadding(margin, margin, margin, margin);
        // Make Clickable
        item.setClickable(true);
        item.setFocusable(true);
        item.setOnClickListener(v -> onClick.run());
        // Ripple Effect
        TypedValue outValue = new TypedValue();
        getContext().getTheme().resolveAttribute(androidx.appcompat.R.attr.selectableItemBackground, outValue, true);
        item.setBackgroundResource(outValue.resourceId);
        // Layout
        item.setTextAlignment(TEXT_ALIGNMENT_VIEW_START);
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        item.setLayoutParams(layoutParams);
        // Add To View
        children.addView(item);
    }
}