Java tutorial
/** * Copyright (c) 2014-present, Facebook, Inc. All rights reserved. * * You are hereby granted a non-exclusive, worldwide, royalty-free license to use, * copy, modify, and distribute this software in source code or binary form for use * in connection with the web services and APIs provided by Facebook. * * As with any software that integrates with the Facebook platform, your use of * this software is subject to the Facebook Developer Principles and Policies * [http://developers.facebook.com/policy/]. This copyright notice shall be * included in all copies or substantial portions of the software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ package com.facebook; import android.annotation.SuppressLint; import android.app.Activity; import android.content.Context; import android.content.ContextWrapper; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Typeface; import android.support.v4.app.Fragment; import android.support.v4.content.ContextCompat; import android.util.AttributeSet; import android.util.TypedValue; import android.view.Gravity; import android.view.View; import android.widget.Button; import android.util.Log; import com.facebook.FacebookException; import com.facebook.FacebookSdk; import com.facebook.R; import com.facebook.appevents.AppEventsLogger; import com.facebook.internal.FragmentWrapper; /** * A base class for a facebook button. */ public abstract class FacebookButtonBase extends Button { private String analyticsButtonCreatedEventName; private String analyticsButtonTappedEventName; private OnClickListener externalOnClickListener; private OnClickListener internalOnClickListener; private boolean overrideCompoundPadding; private int overrideCompoundPaddingLeft; private int overrideCompoundPaddingRight; private FragmentWrapper parentFragment; protected FacebookButtonBase(final Context context, final AttributeSet attrs, int defStyleAttr, int defStyleRes, final String analyticsButtonCreatedEventName, final String analyticsButtonTappedEventName) { super(context, attrs, 0); defStyleRes = (defStyleRes == 0 ? this.getDefaultStyleResource() : defStyleRes); defStyleRes = (defStyleRes == 0 ? R.style.com_facebook_button : defStyleRes); configureButton(context, attrs, defStyleAttr, defStyleRes); this.analyticsButtonCreatedEventName = analyticsButtonCreatedEventName; this.analyticsButtonTappedEventName = analyticsButtonTappedEventName; } protected abstract int getDefaultRequestCode(); /** * Sets the fragment that contains this control. This allows the button to be embedded inside a * Fragment, and will allow the fragment to receive the * {@link Fragment#onActivityResult(int, int, android.content.Intent) onActivityResult} * call rather than the Activity. * * @param fragment the android.support.v4.app.Fragment that contains this control */ public void setFragment(final Fragment fragment) { parentFragment = new FragmentWrapper(fragment); } /** * Sets the fragment that contains this control. This allows the button to be embedded inside a * Fragment, and will allow the fragment to receive the * {@link Fragment#onActivityResult(int, int, android.content.Intent) onActivityResult} * call rather than the Activity. * * @param fragment the android.app.Fragment that contains this control */ public void setFragment(final android.app.Fragment fragment) { parentFragment = new FragmentWrapper(fragment); } /** * Gets the fragment that contains this control. * @return The android.support.v4.app.Fragment that contains this control. */ public Fragment getFragment() { return (parentFragment != null) ? parentFragment.getSupportFragment() : null; } /** * Gets the fragment that contains this control. * @return The android.app.Fragment that contains this control. */ public android.app.Fragment getNativeFragment() { return (parentFragment != null) ? parentFragment.getNativeFragment() : null; } @Override public void setOnClickListener(final OnClickListener l) { this.externalOnClickListener = l; } /** * Returns the request code used for this Button. * * @return the request code. */ public int getRequestCode() { return getDefaultRequestCode(); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (!isInEditMode()) { logButtonCreated(getContext()); } } @Override protected void onDraw(Canvas canvas) { boolean centered = (this.getGravity() & Gravity.CENTER_HORIZONTAL) != 0; if (centered) { // if the text is centered, we need to adjust the frame for the titleLabel based on the // size of the text in order to keep the text centered in the button without adding // extra blank space to the right when unnecessary // 1. the text fits centered within the button without colliding with the image // (imagePaddingWidth) // 2. the text would run into the image, so adjust the insets to effectively left align // it (textPaddingWidth) final int compoundPaddingLeft = getCompoundPaddingLeft(); final int compoundPaddingRight = getCompoundPaddingRight(); final int compoundDrawablePadding = getCompoundDrawablePadding(); final int textX = compoundPaddingLeft + compoundDrawablePadding; final int textContentWidth = getWidth() - textX - compoundPaddingRight; final int textWidth = measureTextWidth(getText().toString()); final int textPaddingWidth = (textContentWidth - textWidth) / 2; final int imagePaddingWidth = (compoundPaddingLeft - getPaddingLeft()) / 2; final int inset = Math.min(textPaddingWidth, imagePaddingWidth); this.overrideCompoundPaddingLeft = compoundPaddingLeft - inset; this.overrideCompoundPaddingRight = compoundPaddingRight + inset; this.overrideCompoundPadding = true; } super.onDraw(canvas); this.overrideCompoundPadding = false; } @Override public int getCompoundPaddingLeft() { return (this.overrideCompoundPadding ? this.overrideCompoundPaddingLeft : super.getCompoundPaddingLeft()); } @Override public int getCompoundPaddingRight() { return (this.overrideCompoundPadding ? this.overrideCompoundPaddingRight : super.getCompoundPaddingRight()); } protected Activity getActivity() { Context context = getContext(); while (!(context instanceof Activity) && context instanceof ContextWrapper) { context = ((ContextWrapper) context).getBaseContext(); } if (context instanceof Activity) { return (Activity) context; } throw new FacebookException("Unable to get Activity."); } protected int getDefaultStyleResource() { return 0; } protected int measureTextWidth(final String text) { return (int) Math.ceil(getPaint().measureText(text)); } protected void configureButton(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) { parseBackgroundAttributes(context, attrs, defStyleAttr, defStyleRes); parseCompoundDrawableAttributes(context, attrs, defStyleAttr, defStyleRes); parseContentAttributes(context, attrs, defStyleAttr, defStyleRes); parseTextAttributes(context, attrs, defStyleAttr, defStyleRes); setupOnClickListener(); } protected void callExternalOnClickListener(final View v) { if (externalOnClickListener != null) { externalOnClickListener.onClick(v); } } protected void setInternalOnClickListener(final OnClickListener l) { internalOnClickListener = l; } private void logButtonCreated(final Context context) { AppEventsLogger logger = AppEventsLogger.newLogger(context); logger.logSdkEvent(analyticsButtonCreatedEventName, null, null); } private void logButtonTapped(final Context context) { AppEventsLogger logger = AppEventsLogger.newLogger(context); logger.logSdkEvent(analyticsButtonTappedEventName, null, null); } private void parseBackgroundAttributes(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) { // TODO, figure out why com_facebook_button_like_background.xml doesn't work in designers if (isInEditMode()) { return; } final int attrsResources[] = { android.R.attr.background, }; final TypedArray a = context.getTheme().obtainStyledAttributes(attrs, attrsResources, defStyleAttr, defStyleRes); try { if (a.hasValue(0)) { int backgroundResource = a.getResourceId(0, 0); if (backgroundResource != 0) { setBackgroundResource(backgroundResource); } else { setBackgroundColor(a.getColor(0, 0)); } } else { // fallback, if no background specified, fill with Facebook blue setBackgroundColor(ContextCompat.getColor(context, R.color.com_facebook_blue)); } } finally { a.recycle(); } } @SuppressLint("ResourceType") private void parseCompoundDrawableAttributes(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) { final int attrsResources[] = { android.R.attr.drawableLeft, android.R.attr.drawableTop, android.R.attr.drawableRight, android.R.attr.drawableBottom, android.R.attr.drawablePadding, }; final TypedArray a = context.getTheme().obtainStyledAttributes(attrs, attrsResources, defStyleAttr, defStyleRes); try { setCompoundDrawablesWithIntrinsicBounds(a.getResourceId(0, 0), a.getResourceId(1, 0), a.getResourceId(2, 0), a.getResourceId(3, 0)); setCompoundDrawablePadding(a.getDimensionPixelSize(4, 0)); } finally { a.recycle(); } } private void parseContentAttributes(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) { final int attrsResources[] = { android.R.attr.paddingLeft, android.R.attr.paddingTop, android.R.attr.paddingRight, android.R.attr.paddingBottom, }; final TypedArray a = context.getTheme().obtainStyledAttributes(attrs, attrsResources, defStyleAttr, defStyleRes); try { setPadding(a.getDimensionPixelSize(0, 0), a.getDimensionPixelSize(1, 0), a.getDimensionPixelSize(2, 0), a.getDimensionPixelSize(3, 0)); } finally { a.recycle(); } } private void parseTextAttributes(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) { final int colorResources[] = { android.R.attr.textColor, }; final TypedArray colorAttrs = context.getTheme().obtainStyledAttributes(attrs, colorResources, defStyleAttr, defStyleRes); try { setTextColor(colorAttrs.getColor(0, Color.WHITE)); } finally { colorAttrs.recycle(); } final int gravityResources[] = { android.R.attr.gravity, }; final TypedArray gravityAttrs = context.getTheme().obtainStyledAttributes(attrs, gravityResources, defStyleAttr, defStyleRes); try { setGravity(gravityAttrs.getInt(0, Gravity.CENTER)); } finally { gravityAttrs.recycle(); } final int attrsResources[] = { android.R.attr.textSize, android.R.attr.textStyle, android.R.attr.text, }; final TypedArray a = context.getTheme().obtainStyledAttributes(attrs, attrsResources, defStyleAttr, defStyleRes); try { setTextSize(TypedValue.COMPLEX_UNIT_PX, a.getDimensionPixelSize(0, 0)); setTypeface(Typeface.defaultFromStyle(a.getInt(1, Typeface.BOLD))); setText(a.getString(2)); } finally { a.recycle(); } } private void setupOnClickListener() { // set the listener on super so that consumers can set another listener that this will // forward to super.setOnClickListener(new OnClickListener() { @Override public void onClick(final View v) { logButtonTapped(getContext()); if (FacebookButtonBase.this.internalOnClickListener != null) { FacebookButtonBase.this.internalOnClickListener.onClick(v); } else if (FacebookButtonBase.this.externalOnClickListener != null) { FacebookButtonBase.this.externalOnClickListener.onClick(v); } } }); } }