Java tutorial
/* * Copyright (C) 2010 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.v7.internal.view.menu; import android.content.Context; import android.content.res.Configuration; import android.content.res.Resources; import android.content.res.TypedArray; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.os.Build; import android.support.v4.view.GravityCompat; import android.support.v4.view.ViewCompat; import android.support.v7.appcompat.R; import android.support.v7.internal.text.AllCapsTransformationMethod; import android.support.v7.internal.widget.CompatTextView; import android.support.v7.widget.ActionMenuView; import android.support.v7.widget.ListPopupWindow; import android.text.TextUtils; import android.text.method.TransformationMethod; import android.util.AttributeSet; import android.view.Gravity; import android.view.MotionEvent; import android.view.View; import android.widget.Toast; import java.util.Locale; /** * @hide */ public class ActionMenuItemView extends CompatTextView implements MenuView.ItemView, View.OnClickListener, View.OnLongClickListener, ActionMenuView.ActionMenuChildView { private static final String TAG = "ActionMenuItemView"; private MenuItemImpl mItemData; private CharSequence mTitle; private Drawable mIcon; private MenuBuilder.ItemInvoker mItemInvoker; private ListPopupWindow.ForwardingListener mForwardingListener; private PopupCallback mPopupCallback; private boolean mAllowTextWithIcon; private boolean mExpandedFormat; private int mMinWidth; private int mSavedPaddingLeft; private static final int MAX_ICON_SIZE = 32; // dp private int mMaxIconSize; public ActionMenuItemView(Context context) { this(context, null); } public ActionMenuItemView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ActionMenuItemView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); final Resources res = context.getResources(); mAllowTextWithIcon = res.getBoolean(R.bool.abc_config_allowActionMenuItemTextWithIcon); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ActionMenuItemView, defStyle, 0); mMinWidth = a.getDimensionPixelSize(R.styleable.ActionMenuItemView_android_minWidth, 0); a.recycle(); final float density = res.getDisplayMetrics().density; mMaxIconSize = (int) (MAX_ICON_SIZE * density + 0.5f); setOnClickListener(this); setOnLongClickListener(this); mSavedPaddingLeft = -1; } public void onConfigurationChanged(Configuration newConfig) { if (Build.VERSION.SDK_INT >= 8) { super.onConfigurationChanged(newConfig); } mAllowTextWithIcon = getContext().getResources() .getBoolean(R.bool.abc_config_allowActionMenuItemTextWithIcon); updateTextButtonVisibility(); } @Override public void setPadding(int l, int t, int r, int b) { mSavedPaddingLeft = l; super.setPadding(l, t, r, b); } public MenuItemImpl getItemData() { return mItemData; } public void initialize(MenuItemImpl itemData, int menuType) { mItemData = itemData; setIcon(itemData.getIcon()); setTitle(itemData.getTitleForItemView(this)); // Title only takes effect if there is no icon setId(itemData.getItemId()); setVisibility(itemData.isVisible() ? View.VISIBLE : View.GONE); setEnabled(itemData.isEnabled()); if (itemData.hasSubMenu()) { if (mForwardingListener == null) { mForwardingListener = new ActionMenuItemForwardingListener(); } } } @Override public boolean onTouchEvent(MotionEvent e) { if (mItemData.hasSubMenu() && mForwardingListener != null && mForwardingListener.onTouch(this, e)) { return true; } return super.onTouchEvent(e); } @Override public void onClick(View v) { if (mItemInvoker != null) { mItemInvoker.invokeItem(mItemData); } } public void setItemInvoker(MenuBuilder.ItemInvoker invoker) { mItemInvoker = invoker; } public void setPopupCallback(PopupCallback popupCallback) { mPopupCallback = popupCallback; } public boolean prefersCondensedTitle() { return true; } public void setCheckable(boolean checkable) { // TODO Support checkable action items } public void setChecked(boolean checked) { // TODO Support checkable action items } public void setExpandedFormat(boolean expandedFormat) { if (mExpandedFormat != expandedFormat) { mExpandedFormat = expandedFormat; if (mItemData != null) { mItemData.actionFormatChanged(); } } } private void updateTextButtonVisibility() { boolean visible = !TextUtils.isEmpty(mTitle); visible &= mIcon == null || (mItemData.showsTextAsAction() && (mAllowTextWithIcon || mExpandedFormat)); setText(visible ? mTitle : null); } public void setIcon(Drawable icon) { mIcon = icon; if (icon != null) { int width = icon.getIntrinsicWidth(); int height = icon.getIntrinsicHeight(); if (width > mMaxIconSize) { final float scale = (float) mMaxIconSize / width; width = mMaxIconSize; height *= scale; } if (height > mMaxIconSize) { final float scale = (float) mMaxIconSize / height; height = mMaxIconSize; width *= scale; } icon.setBounds(0, 0, width, height); } setCompoundDrawables(icon, null, null, null); updateTextButtonVisibility(); } public boolean hasText() { return !TextUtils.isEmpty(getText()); } public void setShortcut(boolean showShortcut, char shortcutKey) { // Action buttons don't show text for shortcut keys. } public void setTitle(CharSequence title) { mTitle = title; setContentDescription(mTitle); updateTextButtonVisibility(); } public boolean showsIcon() { return true; } public boolean needsDividerBefore() { return hasText() && mItemData.getIcon() == null; } public boolean needsDividerAfter() { return hasText(); } @Override public boolean onLongClick(View v) { if (hasText()) { // Don't show the cheat sheet for items that already show text. return false; } final int[] screenPos = new int[2]; final Rect displayFrame = new Rect(); getLocationOnScreen(screenPos); getWindowVisibleDisplayFrame(displayFrame); final Context context = getContext(); final int width = getWidth(); final int height = getHeight(); final int midy = screenPos[1] + height / 2; int referenceX = screenPos[0] + width / 2; if (ViewCompat.getLayoutDirection(v) == ViewCompat.LAYOUT_DIRECTION_LTR) { final int screenWidth = context.getResources().getDisplayMetrics().widthPixels; referenceX = screenWidth - referenceX; // mirror } Toast cheatSheet = Toast.makeText(context, mItemData.getTitle(), Toast.LENGTH_SHORT); if (midy < displayFrame.height()) { // Show along the top; follow action buttons cheatSheet.setGravity(Gravity.TOP | GravityCompat.END, referenceX, height); } else { // Show along the bottom center cheatSheet.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, height); } cheatSheet.show(); return true; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final boolean textVisible = hasText(); if (textVisible && mSavedPaddingLeft >= 0) { super.setPadding(mSavedPaddingLeft, getPaddingTop(), getPaddingRight(), getPaddingBottom()); } super.onMeasure(widthMeasureSpec, heightMeasureSpec); final int widthMode = MeasureSpec.getMode(widthMeasureSpec); final int widthSize = MeasureSpec.getSize(widthMeasureSpec); final int oldMeasuredWidth = getMeasuredWidth(); final int targetWidth = widthMode == MeasureSpec.AT_MOST ? Math.min(widthSize, mMinWidth) : mMinWidth; if (widthMode != MeasureSpec.EXACTLY && mMinWidth > 0 && oldMeasuredWidth < targetWidth) { // Remeasure at exactly the minimum width. super.onMeasure(MeasureSpec.makeMeasureSpec(targetWidth, MeasureSpec.EXACTLY), heightMeasureSpec); } if (!textVisible && mIcon != null) { // TextView won't center compound drawables in both dimensions without // a little coercion. Pad in to center the icon after we've measured. final int w = getMeasuredWidth(); final int dw = mIcon.getBounds().width(); super.setPadding((w - dw) / 2, getPaddingTop(), getPaddingRight(), getPaddingBottom()); } } private class ActionMenuItemForwardingListener extends ListPopupWindow.ForwardingListener { public ActionMenuItemForwardingListener() { super(ActionMenuItemView.this); } @Override public ListPopupWindow getPopup() { if (mPopupCallback != null) { return mPopupCallback.getPopup(); } return null; } @Override protected boolean onForwardingStarted() { // Call the invoker, then check if the expected popup is showing. if (mItemInvoker != null && mItemInvoker.invokeItem(mItemData)) { final ListPopupWindow popup = getPopup(); return popup != null && popup.isShowing(); } return false; } @Override protected boolean onForwardingStopped() { final ListPopupWindow popup = getPopup(); if (popup != null) { popup.dismiss(); return true; } return false; } } public static abstract class PopupCallback { public abstract ListPopupWindow getPopup(); } }