我的 GifFun 之旅 - Klien-m's 博客

GifFun 是一个由《第一行代码》作者郭霖开源的一个项目。用户可以登录分享 Gif 图，查看别人分享的 Gif 图等。

关于在学习 GifFun 项目中的一些收获

Github
Gitee

在自定义 Application 中进行全局的初始化操作。
封装 SharedPreferences 的操作。
定义常量标识符。
导入 module api project('module name')
umeng（数据统计）、 Litepal、 gson、 eventbus（事件发布订阅，观察者？）、 okhttp、Glide图片加载、implementation 'jp.wasabeef:glide-transformations:4.1.0'、'de.hdodenhof:circleimageview:2.1.0'、七牛云、Android-Image-Cropper、filebrowser、PhotoView
接口指定方法，继承接口则有此方法
设置 activity 的基类，就像《第二行代码》里讲的
日志操作的扩展工具类，就像《第二行代码》里讲的
AndroidVersion.kt
looper
集成 Toast 方法的 Context 使用 Application 的 Context，当前所在代码类有 Context 则使用当前的。
Nickname（昵称）
isNotEmpty(str) 等价于 str != null && str.length > 0
isNotBlank(str) 等价于 str != null && str.length > 0 && str.trim().length() > 0
@JvmStatic 指定如果它是函数，则需要从此元素生成额外的静态方法。如果此元素是属性，则应生成额外的静态 getter / setter 方法。
api 和 implementation
implementation “androidx.palette:palette:1.0.0” 拾色器
actionStart()
setupViews() 初始化布局控件 UserInfo modify
CountDownTimer 计时器

com.quxianggif.core

单位转换工具类，会根据手机的分辨率来进行单位转换

/**
 * 根据手机的分辨率将dp转成为px
 */
fun dp2px(dp: Float): Int {
    val scale = GifFun.getContext().resources.displayMetrics.density
    return (dp * scale + 0.5f).toInt()
}

/**
 * 根据手机的分辨率将px转成dp
 */
fun px2dp(px: Float): Int {
    val scale = GifFun.getContext().resources.displayMetrics.density
    return (px / scale + 0.5f).toInt()
}

Toast

private var toast: Toast? = null

    /**
     * 弹出Toast信息。如果不是在主线程中调用此方法，Toast信息将会不显示。
     *
     * @param content
     * Toast中显示的内容
     */
    @SuppressLint("ShowToast")
    @JvmOverloads
    fun showToast(content: String, duration: Int = Toast.LENGTH_SHORT) {
        if (Looper.myLooper() == Looper.getMainLooper()) {
            if (toast == null) {
                toast = Toast.makeText(GifFun.getContext(), content, duration)
            } else {
                toast?.setText(content)
            }
            toast?.show()
        }
    }

    /**
     * 切换到主线程后弹出Toast信息。此方法不管是在子线程还是主线程中，都可以成功弹出Toast信息。
     *
     * @param content
     * Toast中显示的内容
     * @param duration
     * Toast显示的时长
     */
    @SuppressLint("ShowToast")
    @JvmOverloads
    fun showToastOnUiThread(content: String, duration: Int = Toast.LENGTH_SHORT) {
        GifFun.getHandler().post {
            if (toast == null) {
                toast = Toast.makeText(GifFun.getContext(), content, duration)
            } else {
                toast?.setText(content)
            }
            toast?.show()
        }
    }

com.quxianggif.main

comments

取消数据改变时的动画，防止闪烁

(recyclerView.itemAnimator as SimpleItemAnimator).supportsChangeAnimations = false

当知道 Adapter 内 Item 的改变不会影响 RecyclerView 宽高的时候，可以设置为 true 让 RecyclerView 避免重新计算大小，并通过 Adapter 的增删改查方法刷新 RecyclerView。在需要改变宽高的时候就用 notifyDataSetChanged() 刷新。
```
recyclerView.setHasFixedSize(true)
```

自定义 RecyclerView，根据 item 高度改变 RecyclerView 高度

class TopCommentsRecyclerView : RecyclerView {

    constructor(context: Context) : super(context)

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)

    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(
        context,
        attrs,
        defStyleAttr
    )

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        //  AT_MOST参数表示控件可以自由调整大小，最大不超过Integer.MAX_VALUE/4
        val height = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE shr 2, MeasureSpec.AT_MOST)
        super.onMeasure(widthMeasureSpec, height)
    }

}

common

将状态栏设置成透明

/**
 * 将状态栏设置成透明。只适配Android 5.0以上系统的手机。
 */
protected fun transparentStatusBar() {
    if (AndroidVersion.hasLollipop()) {
        val decorView = window.decorView
        decorView.systemUiVisibility =
            View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
        window.statusBarColor = Color.TRANSPARENT
    }
}

隐藏软键盘

/**
 * 隐藏软键盘。
 */
fun hideSoftKeyboard() {
    try {
        val view = currentFocus
        if (view != null) {
            val binder = view.windowToken
            val manager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
            manager.hideSoftInputFromWindow(binder, InputMethodManager.HIDE_NOT_ALWAYS)
        }
    } catch (e: Exception) {
        logWarn(TAG, e.message, e)
    }

}

显示软键盘

/**
 * 显示软键盘。
 */
fun showSoftKeyboard(editText: EditText?) {
    try {
        if (editText != null) {
            editText.requestFocus()
            val manager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
            manager.showSoftInput(editText, 0)
        }
    } catch (e: Exception) {
        logWarn(TAG, e.message, e)
    }

}

跳转到应用设置界面

val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
val uri = Uri.fromParts("package", GlobalUtil.appPackage, null)
intent.data = uri

feeds

ImageView、TextView 等控件具有 android:layout_gravity 属性

发布文章时间显示

private fun getDraftTime(draftMillis: Long): String {
    val currentMillis = System.currentTimeMillis()
    val calendar = Calendar.getInstance()
    calendar.timeInMillis = currentMillis
    val currentYear = calendar.get(Calendar.YEAR)
    val currentMonth = calendar.get(Calendar.MONTH)
    val currentDay = calendar.get(Calendar.DAY_OF_MONTH)
    calendar.timeInMillis = draftMillis
    val draftYear = calendar.get(Calendar.YEAR)
    val draftMonth = calendar.get(Calendar.MONTH)
    val draftDay = calendar.get(Calendar.DAY_OF_MONTH)
    return if (currentYear == draftYear && currentMonth == draftMonth && currentDay == draftDay) {
        // 当天的草稿只显示时间
        SimpleDateFormat("HH:mm", Locale.getDefault()).format(Date(draftMillis))
    } else {
        if (currentYear == draftYear) {
            // 当年的草稿只显示月日
            SimpleDateFormat("MM-dd", Locale.getDefault()).format(Date(draftMillis))
        } else {
            // 隔年的草稿显示完整年月日
            SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(Date(draftMillis))
        }
    }
}

ContextMenu
SparseArray

init.ui

/**
 * 跳转到下一个Activity。如果在闪屏界面停留的时间还不足规定最短停留时间，则会在这里等待一会，保证闪屏界面不至于一闪而过。
 */
@Synchronized
open fun forwardToNextActivity(hasNewVersion: Boolean, version: Version?) {
    if (!isForwarding) { // 如果正在跳转或已经跳转到下一个界面，则不再重复执行跳转
        isForwarding = true
        val currentTime = System.currentTimeMillis()
        val timeSpent = currentTime - enterTime
        if (timeSpent < MIN_WAIT_TIME) {
            GlobalUtil.sleep(MIN_WAIT_TIME - timeSpent)
        }
        runOnUiThread {
            if (GifFun.isLogin()) {
                MainActivity.actionStart(this)
                finish()
            } else {
                if (isActive) {
                    LoginActivity.actionStartWithTransition(this, logoView, hasNewVersion, version)
                } else {
                    LoginActivity.actionStart(this, hasNewVersion, version)
                    finish()
                }
            }
        }
    }
}

util

ActivityCollector.kt

/**
 * 应用中所有Activity的管理器，可用于一键杀死所有Activity。
 */
object ActivityCollector {

    private const val TAG = "ActivityCollector"

    private val activityList = ArrayList<WeakReference<Activity>?>()

    fun size(): Int {
        return activityList.size
    }

    fun add(weakRefActivity: WeakReference<Activity>?) {
        activityList.add(weakRefActivity)
    }

    fun remove(weakRefActivity: WeakReference<Activity>?) {
        val result = activityList.remove(weakRefActivity)
        logDebug(TAG, "remove activity reference $result")
    }

    fun finishAll() {
        if (activityList.isNotEmpty()) {
            for (activityWeakReference in activityList) {
                val activity = activityWeakReference?.get()
                if (activity != null && !activity.isFinishing) {
                    activity.finish()
                }
            }
            activityList.clear()
        }
    }
}

ColorUtils.kt

/**
 * Utility methods for working with colors.
 */
object ColorUtils {

    private const val IS_LIGHT = 0
    private const val IS_DARK = 1
    private const val LIGHTNESS_UNKNOWN = 2

    private const val TAG = "ColorUtils"

    /**
     * Set the alpha component of `color` to be `alpha`.
     */
    @CheckResult
    @ColorInt
    fun modifyAlpha(@ColorInt color: Int,
                    @IntRange(from = 0, to = 255) alpha: Int): Int {
        return color and 0x00ffffff or (alpha shl 24)
    }

    /**
     * Set the alpha component of `color` to be `alpha`.
     */
    @CheckResult
    @ColorInt
    fun modifyAlpha(@ColorInt color: Int,
                    @FloatRange(from = 0.0, to = 1.0) alpha: Float): Int {
        return modifyAlpha(color, (255f * alpha).toInt())
    }

    /**
     * 判断传入的图片的颜色属于深色还是浅色。
     * @param bitmap
     * 图片的Bitmap对象。
     * @return 返回true表示图片属于深色，返回false表示图片属于浅色。
     */
    fun isBitmapDark(palette: Palette?, bitmap: Bitmap): Boolean {
        val isDark: Boolean
        val lightness = ColorUtils.isDark(palette)
        if (lightness == ColorUtils.LIGHTNESS_UNKNOWN) {
            isDark = ColorUtils.isDark(bitmap, bitmap.width / 2, 0)
        } else {
            isDark = lightness == ColorUtils.IS_DARK
        }
        return isDark
    }

    /**
     * Checks if the most populous color in the given palette is dark
     *
     *
     * Annoyingly we have to return this Lightness 'enum' rather than a boolean as palette isn't
     * guaranteed to find the most populous color.
     */
    fun isDark(palette: Palette?): Int {
        val mostPopulous = getMostPopulousSwatch(palette) ?: return LIGHTNESS_UNKNOWN
        return if (isDark(mostPopulous.hsl)) IS_DARK else IS_LIGHT
    }

    /**
     * Determines if a given bitmap is dark. This extracts a palette inline so should not be called
     * with a large image!! If palette fails then check the color of the specified pixel
     */
    fun isDark(bitmap: Bitmap, backupPixelX: Int, backupPixelY: Int): Boolean {
        // first try palette with a small color quant size
        val palette = Palette.from(bitmap).maximumColorCount(3).generate()
        return if (palette.swatches.size > 0) {
            isDark(palette) == IS_DARK
        } else {
            // if palette failed, then check the color of the specified pixel
            isDark(bitmap.getPixel(backupPixelX, backupPixelY))
        }
    }

    /**
     * Convert to HSL & check that the lightness value
     */
    fun isDark(@ColorInt color: Int): Boolean {
        val hsl = FloatArray(3)
        android.support.v4.graphics.ColorUtils.colorToHSL(color, hsl)
        return isDark(hsl)
    }

    /**
     * Check that the lightness value (0–1)
     */
    fun isDark(hsl: FloatArray): Boolean { // @Size(3)
        logDebug(TAG, "hsl[2] is " + hsl[2])
        return hsl[2] < 0.8f
    }

    fun getMostPopulousSwatch(palette: Palette?): Palette.Swatch? {
        var mostPopulous: Palette.Swatch? = null
        if (palette != null) {
            for (swatch in palette.swatches) {
                if (mostPopulous == null || swatch.population > mostPopulous.population) {
                    mostPopulous = swatch
                }
            }
        }
        return mostPopulous
    }

}

DateUtil.kt

/**
 * 时间和日期工具类。
 */
object DateUtil {

    private const val MINUTE = (60 * 1000).toLong()

    private const val HOUR = 60 * MINUTE

    private const val DAY = 24 * HOUR

    private const val WEEK = 7 * DAY

    private const val MONTH = 4 * WEEK

    private const val YEAR = 365 * DAY

    /**
     * 根据传入的Unix时间戳，获取转换过后更加易读的时间格式。
     * @param dateMillis
     * Unix时间戳
     * @return 转换过后的时间格式，如2分钟前，1小时前。
     */
    fun getConvertedDate(dateMillis: Long): String {
        val currentMillis = System.currentTimeMillis()
        val timePast = currentMillis - dateMillis
        if (timePast > -MINUTE) { // 采用误差一分钟以内的算法，防止客户端和服务器时间不同步导致的显示问题
            when {
                timePast < HOUR -> {
                    var pastMinutes = timePast / MINUTE
                    if (pastMinutes <= 0) {
                        pastMinutes = 1
                    }
                    return pastMinutes.toString() + GlobalUtil.getString(R.string.minutes_ago)
                }
                timePast < DAY -> {
                    var pastHours = timePast / HOUR
                    if (pastHours <= 0) {
                        pastHours = 1
                    }
                    return pastHours.toString() + GlobalUtil.getString(R.string.hours_ago)
                }
                timePast < WEEK -> {
                    var pastDays = timePast / DAY
                    if (pastDays <= 0) {
                        pastDays = 1
                    }
                    return pastDays.toString() + GlobalUtil.getString(R.string.days_ago)
                }
                timePast < MONTH -> {
                    var pastDays = timePast / WEEK
                    if (pastDays <= 0) {
                        pastDays = 1
                    }
                    return pastDays.toString() + GlobalUtil.getString(R.string.weeks_ago)
                }
                else -> return getDate(dateMillis)
            }
        } else {
            return getDateAndTime(dateMillis)
        }
    }

    fun getTimeLeftTip(timeLeft: Long) = when {
        timeLeft > YEAR -> {
            val year = (timeLeft / YEAR) + 1
            year.toString() + GlobalUtil.getString(R.string.year)
        }
        timeLeft > MONTH -> {
            val month = (timeLeft / MONTH) + 1
            month.toString() + GlobalUtil.getString(R.string.month)
        }
        timeLeft > DAY -> {
            val day = (timeLeft / DAY) + 1
            day.toString() + GlobalUtil.getString(R.string.day)
        }
        timeLeft > HOUR -> {
            val hour = (timeLeft / HOUR) + 1
            hour.toString() + GlobalUtil.getString(R.string.hour)
        }
        timeLeft > MINUTE -> {
            val minute = (timeLeft / MINUTE) + 1
            minute.toString() + GlobalUtil.getString(R.string.minute)
        }
        else -> {
            "1" + GlobalUtil.getString(R.string.minute)
        }
    }

    fun isBlockedForever(timeLeft: Long) = timeLeft > 5 * YEAR

    private fun getDate(dateMillis: Long): String {
        val sdf = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
        return sdf.format(Date(dateMillis))
    }

    private fun getDateAndTime(dateMillis: Long): String {
        val sdf = SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.getDefault())
        return sdf.format(Date(dateMillis))
    }

}

DeviceInfo.kt

/**
 * 提供所有与设备相关的信息。
 */
object DeviceInfo {

    /**
     * 获取当前设备屏幕的宽度，以像素为单位。
     *
     * @return 当前设备屏幕的宽度。
     */
    val screenWidth: Int
        get() {
            val windowManager = GifFun.getContext().getSystemService(Context.WINDOW_SERVICE) as WindowManager
            val metrics = DisplayMetrics()
            if (AndroidVersion.hasJellyBeanMR1()) {
                windowManager.defaultDisplay.getRealMetrics(metrics)
            } else {
                windowManager.defaultDisplay.getMetrics(metrics)
            }
            return metrics.widthPixels
        }

    /**
     * 获取当前设备屏幕的高度，以像素为单位。
     *
     * @return 当前设备屏幕的高度。
     */
    val screenHeight: Int
        get() {
            val windowManager = GifFun.getContext().getSystemService(Context.WINDOW_SERVICE) as WindowManager
            val metrics = DisplayMetrics()
            if (AndroidVersion.hasJellyBeanMR1()) {
                windowManager.defaultDisplay.getRealMetrics(metrics)
            } else {
                windowManager.defaultDisplay.getMetrics(metrics)
            }
            return metrics.heightPixels
        }

}

com.quxianggif.network

MD5.kt

/**
 * MD5加密辅助工具类。
 */
public class MD5 {

    private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

    /**
     * 对传入的字符串进行MD5加密。
     *
     * @param origin 原始字符串。
     * @return 经过MD5加密后的字符串。
     */
    public static String encrypt(String origin) {
        try {
            MessageDigest digest = MessageDigest.getInstance("MD5");
            digest.update(origin.getBytes(Charset.defaultCharset()));
            return new String(toHex(digest.digest()));
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return "";
    }

    /**
     * 获取文件的MD5值。
     *
     * @param path 文件的路径
     * @return 文件的MD5值。
     */
    public static String getFileMD5(String path) {
        try {
            FileInputStream fis = new FileInputStream(path);
            MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] buffer = new byte[1024];
            int length;
            while ((length = fis.read(buffer, 0, 1024)) != -1) {
                md.update(buffer, 0, length);
            }
            BigInteger bigInt = new BigInteger(1, md.digest());
            return bigInt.toString(16).toUpperCase();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    private static char[] toHex(byte[] data) {
        char[] toDigits = DIGITS_UPPER;
        int l = data.length;
        char[] out = new char[l << 1];
        // two characters form the hex value.
        for (int i = 0, j = 0; i < l; i++) {
            out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
            out[j++] = toDigits[0x0F & data[i]];
        }
        return out;
    }
}