BottomNavigationItemView.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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 android.support.design.internal;

import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;

import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.annotation.RestrictTo;
import android.support.design.R;
import android.support.v4.content.ContextCompat;
import android.support.v4.graphics.drawable.DrawableCompat;
import android.support.v4.view.PointerIconCompat;
import android.support.v4.view.ViewCompat;
import android.support.v7.view.menu.MenuItemImpl;
import android.support.v7.view.menu.MenuView;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.TextView;

/**
 * @hide
 */
@RestrictTo(LIBRARY_GROUP)
public class BottomNavigationItemView extends FrameLayout implements MenuView.ItemView {
    public static final int INVALID_ITEM_POSITION = -1;

    private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };

    private final int mDefaultMargin;
    private final int mShiftAmount;
    private final float mScaleUpFactor;
    private final float mScaleDownFactor;

    private boolean mShiftingMode;

    private ImageView mIcon;
    private final TextView mSmallLabel;
    private final TextView mLargeLabel;
    private int mItemPosition = INVALID_ITEM_POSITION;

    private MenuItemImpl mItemData;

    private ColorStateList mIconTint;

    public BottomNavigationItemView(@NonNull Context context) {
        this(context, null);
    }

    public BottomNavigationItemView(@NonNull Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BottomNavigationItemView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        final Resources res = getResources();
        int inactiveLabelSize =
                res.getDimensionPixelSize(R.dimen.design_bottom_navigation_text_size);
        int activeLabelSize = res.getDimensionPixelSize(
                R.dimen.design_bottom_navigation_active_text_size);
        mDefaultMargin = res.getDimensionPixelSize(R.dimen.design_bottom_navigation_margin);
        mShiftAmount = inactiveLabelSize - activeLabelSize;
        mScaleUpFactor = 1f * activeLabelSize / inactiveLabelSize;
        mScaleDownFactor = 1f * inactiveLabelSize / activeLabelSize;

        LayoutInflater.from(context).inflate(R.layout.design_bottom_navigation_item, this, true);
        setBackgroundResource(R.drawable.design_bottom_navigation_item_background);
        mIcon = (ImageView) findViewById(R.id.icon);
        mSmallLabel = (TextView) findViewById(R.id.smallLabel);
        mLargeLabel = (TextView) findViewById(R.id.largeLabel);
    }

    @Override
    public void initialize(MenuItemImpl itemData, int menuType) {
        mItemData = itemData;
        setCheckable(itemData.isCheckable());
        setChecked(itemData.isChecked());
        setEnabled(itemData.isEnabled());
        setIcon(itemData.getIcon());
        setTitle(itemData.getTitle());
        setId(itemData.getItemId());
    }

    public void setItemPosition(int position) {
        mItemPosition = position;
    }

    public int getItemPosition() {
        return mItemPosition;
    }

    public void setShiftingMode(boolean enabled) {
        mShiftingMode = enabled;
    }

    @Override
    public MenuItemImpl getItemData() {
        return mItemData;
    }

    @Override
    public void setTitle(CharSequence title) {
        mSmallLabel.setText(title);
        mLargeLabel.setText(title);
        setContentDescription(title);
    }

    @Override
    public void setCheckable(boolean checkable) {
        refreshDrawableState();
    }

    @Override
    public void setChecked(boolean checked) {
        ViewCompat.setPivotX(mLargeLabel, mLargeLabel.getWidth() / 2);
        ViewCompat.setPivotY(mLargeLabel, mLargeLabel.getBaseline());
        ViewCompat.setPivotX(mSmallLabel, mSmallLabel.getWidth() / 2);
        ViewCompat.setPivotY(mSmallLabel, mSmallLabel.getBaseline());
        if (mShiftingMode) {
            if (checked) {
                LayoutParams iconParams = (LayoutParams) mIcon.getLayoutParams();
                iconParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
                iconParams.topMargin = mDefaultMargin;
                mIcon.setLayoutParams(iconParams);
                mLargeLabel.setVisibility(VISIBLE);
                ViewCompat.setScaleX(mLargeLabel, 1f);
                ViewCompat.setScaleY(mLargeLabel, 1f);
            } else {
                LayoutParams iconParams = (LayoutParams) mIcon.getLayoutParams();
                iconParams.gravity = Gravity.CENTER;
                iconParams.topMargin = mDefaultMargin;
                mIcon.setLayoutParams(iconParams);
                mLargeLabel.setVisibility(INVISIBLE);
                ViewCompat.setScaleX(mLargeLabel, 0.5f);
                ViewCompat.setScaleY(mLargeLabel, 0.5f);
            }
            mSmallLabel.setVisibility(INVISIBLE);
        } else {
            if (checked) {
                LayoutParams iconParams = (LayoutParams) mIcon.getLayoutParams();
                iconParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
                iconParams.topMargin = mDefaultMargin + mShiftAmount;
                mIcon.setLayoutParams(iconParams);
                mLargeLabel.setVisibility(VISIBLE);
                mSmallLabel.setVisibility(INVISIBLE);

                ViewCompat.setScaleX(mLargeLabel, 1f);
                ViewCompat.setScaleY(mLargeLabel, 1f);
                ViewCompat.setScaleX(mSmallLabel, mScaleUpFactor);
                ViewCompat.setScaleY(mSmallLabel, mScaleUpFactor);
            } else {
                LayoutParams iconParams = (LayoutParams) mIcon.getLayoutParams();
                iconParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
                iconParams.topMargin = mDefaultMargin;
                mIcon.setLayoutParams(iconParams);
                mLargeLabel.setVisibility(INVISIBLE);
                mSmallLabel.setVisibility(VISIBLE);

                ViewCompat.setScaleX(mLargeLabel, mScaleDownFactor);
                ViewCompat.setScaleY(mLargeLabel, mScaleDownFactor);
                ViewCompat.setScaleX(mSmallLabel, 1f);
                ViewCompat.setScaleY(mSmallLabel, 1f);
            }
        }

        refreshDrawableState();
    }

    @Override
    public void setEnabled(boolean enabled) {
        super.setEnabled(enabled);
        mSmallLabel.setEnabled(enabled);
        mLargeLabel.setEnabled(enabled);
        mIcon.setEnabled(enabled);

        if (enabled) {
            ViewCompat.setPointerIcon(this,
                    PointerIconCompat.getSystemIcon(getContext(), PointerIconCompat.TYPE_HAND));
        } else {
            ViewCompat.setPointerIcon(this, null);
        }

    }

    @Override
    public int[] onCreateDrawableState(final int extraSpace) {
        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
        if (mItemData != null && mItemData.isCheckable() && mItemData.isChecked()) {
            mergeDrawableStates(drawableState, CHECKED_STATE_SET);
        }
        return drawableState;
    }

    @Override
    public void setShortcut(boolean showShortcut, char shortcutKey) {
    }

    @Override
    public void setIcon(Drawable icon) {
        if (icon != null) {
            Drawable.ConstantState state = icon.getConstantState();
            icon = DrawableCompat.wrap(state == null ? icon : state.newDrawable()).mutate();
            DrawableCompat.setTintList(icon, mIconTint);
        }
        mIcon.setImageDrawable(icon);
    }

    @Override
    public boolean prefersCondensedTitle() {
        return false;
    }

    @Override
    public boolean showsIcon() {
        return true;
    }

    public void setIconTintList(ColorStateList tint) {
        mIconTint = tint;
        if (mItemData != null) {
            // Update the icon so that the tint takes effect
            setIcon(mItemData.getIcon());
        }
    }

    public void setTextColor(ColorStateList color) {
        mSmallLabel.setTextColor(color);
        mLargeLabel.setTextColor(color);
    }

    public void setItemBackground(int background) {
        Drawable backgroundDrawable = background == 0
                ? null : ContextCompat.getDrawable(getContext(), background);
        ViewCompat.setBackground(this, backgroundDrawable);
    }
}