Java tutorial
/* * 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 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; import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP; /** * @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); } }