feat: SnapShot Toast in Multiple Situation (#1363)

* feat: 快照成功toast判断截图tip

"快照成功"判断是否存在截图toast提示

* perf: 简写为also函数 & 布尔值语义纠正

* feat: 增加第三种情况demo

- 新增"目标App疑似截屏保护",判定逻辑ing
- when枚举

* feat: App拒绝提供画面逻辑 (方差法)

* fix: gpu位图崩溃隐患&防截屏判定逻辑

- 修复部分设备上 HARDWARE 位图无法直接读取像素导致的崩溃问题（强制转为 ARGB_8888）
- 引入 `recycleIfTemp` 辅助函数，统一并安全回收临时 Bitmap
- 增加裁剪状态栏逻辑，并将边缘忽略比例由 0.2 调整为 0.1
- 优化判定算法：引入纯黑极值像素占比统计，放宽方差阈值

* perf: 删除状态栏预处理&降低图片边缘排除阈值

- 调用函数涂黑属于写操作,且与忽略图片边缘操作本质相同,纯副操作.故删除
- 调低排除四周图片阈值至8%,降低纯黑界面却有字(正常)情况下错误识别

* perf: 死代码

bitmap !== bitmap为不成立,啥也没干

* perf: 简化toast语句

* fix: toast text

---------

Co-authored-by: 二刺螈 <i@songe.li>

app/src/main/kotlin/li/songe/gkd/util/SnapshotExt.kt

@@ -2,6 +2,7 @@ package li.songe.gkd.util
 
 import android.graphics.Bitmap
 import androidx.core.graphics.createBitmap
+import androidx.core.graphics.scale
 import androidx.core.graphics.set
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.async
@@ -122,7 +123,73 @@ object SnapshotExt {
         }
         return tempBp
     }
+    // 截图三种状态
+    private enum class ScreenWhy {
+        Pass,
+        NotHave,
+        Block,
+    }
+    // App拒绝提供画面判定逻辑
+    private fun isAppProtected(bitmap: Bitmap): Boolean {
+        fun Bitmap.recycleIfTemp() { if (this !== bitmap) recycle() }
+        // 缩小图片
+        val size = 64
+        val scaled = bitmap.scale(size, size, false)
 
+        /* 强制转为 ARGB_8888（软件位图）
+        部分设备,Android版本scale()返回仍是HARDWARE
+        bitmap在 gpu内存,cpu无法直接读,会崩溃
+         */
+        val softBitmap = if (scaled.config == Bitmap.Config.HARDWARE) {
+            val copy = scaled.copy(Bitmap.Config.ARGB_8888, false)
+            scaled.recycleIfTemp()
+            copy ?: return false  // copy 失败（极端 OOM）直接返回，不继续执行
+        } else {
+            scaled
+        }
+        //  像素一次性读取到数组
+        val pixels = IntArray(size * size)
+        softBitmap.getPixels(pixels, 0, size, 0, 0, size, size)
+        softBitmap.recycleIfTemp()
+        val ignore = (size * 0.08).toInt()  //  忽略图片边缘
+        // 统计变量
+        var sum = 0.0  //  亮度总和
+        var sumSq = 0.0  //  平方总和
+        var count = 0 // 样本数量
+        //  统计极值像素占比
+        var nearBlackCount = 0
+        // 采样
+        val step = 2 //隔一个像素取样
+        for (y in ignore until size - ignore step step) {  // ignore(忽略边缘)
+            for (x in ignore until size - ignore step step) {
+                // 提取RGB
+                val p = pixels[y * size + x]
+                val r = (p shr 16) and 0xff
+                val g = (p shr 8) and 0xff
+                val b = p and 0xff
+                // 计算亮度
+                val l = 0.299 * r + 0.587 * g + 0.114 * b
+                // 统计
+                sum += l
+                sumSq += l * l
+                count++
+                if (l < 10) nearBlackCount++
+            }
+        }
+        // 防止除零
+        if (count == 0) return false
+        // 平均值和方差计算
+        val mean = sum / count
+        val variance = sumSq / count - mean * mean
+
+        // 极值(纯黑)像素占比
+        val blackRatio = nearBlackCount.toDouble() / count
+        // 判断条件拆分,低方差+像素高度集中在极端值
+        val isNearlyUniform = variance < 15.0  // 放宽，包容轻微噪点
+        val isDominantlyBlack = blackRatio > 0.85 && mean < 15.0
+        // 判断值设定
+        return isNearlyUniform && (isDominantlyBlack)
+    }
     private val captureLoading = MutableStateFlow(false)
     suspend fun captureSnapshot(forcedCropStatusBar: Boolean = false): ComplexSnapshot {
         if (A11yRuleEngine.instance == null) {
@@ -139,7 +206,7 @@ object SnapshotExt {
             if (storeFlow.value.showSaveSnapshotToast) {
                 toast("正在保存快照...", forced = true)
             }
-            val (snapshot, bitmap) = coroutineScope {
+            val (snapshot, screenResult) = coroutineScope {  // 快照数据+截图(图片 && 状态)
                 val d1 = async(Dispatchers.IO) {
                     val appId = rootNode.packageName.toString()
                     var activityId = shizukuContextFlow.value.topCpn()?.className
@@ -168,19 +235,34 @@ object SnapshotExt {
                     )
                 }
                 val d2 = async(Dispatchers.IO) {
-                    (A11yRuleEngine.screenshot()
-                        ?: ScreenshotService.screenshot()
-                        ?: emptyScreenBitmap("无截图权限\n请自行替换")
-                            ).let {
-                            if (storeFlow.value.hideSnapshotStatusBar && (forcedCropStatusBar || BarUtils.checkStatusBarVisible() == true)) {
-                                cropBitmapStatusBar(it)
-                            } else {
-                                it
-                            }
+                    val rawPicture =  // 获取原始图片
+                        A11yRuleEngine.screenshot()  // 无障碍
+                        ?: ScreenshotService.screenshot() // 截图服务
+
+                    val (finalBitmap, status) = when {
+                        rawPicture == null -> {
+                            emptyScreenBitmap("无截图权限\n请自行替换") to ScreenWhy.NotHave
                         }
+                        isAppProtected(rawPicture) -> {
+                            rawPicture to ScreenWhy.Block
+                        }
+                        else -> {
+                            rawPicture to ScreenWhy.Pass
+                        }
+                    }
+
+                    val processedBitmap = if (status == ScreenWhy.Pass &&
+                        storeFlow.value.hideSnapshotStatusBar && (forcedCropStatusBar || BarUtils.checkStatusBarVisible() == true)) {
+                          cropBitmapStatusBar(finalBitmap)
+                    } else {
+                        finalBitmap
+                    }
+                    processedBitmap to status
                 }
                 d1.await() to d2.await()
             }
+
+            val (bitmap, currentStatus) = screenResult // 拆开(图片+状态)
             withContext(Dispatchers.IO) {
                 snapshotParentPath(snapshot.id).autoMk()
                 screenshotFile(snapshot.id).outputStream().use { stream ->
@@ -196,7 +278,12 @@ object SnapshotExt {
                 )
                 DbSet.snapshotDao.insert(snapshot.toSnapshot())
             }
-            toast("快照成功", forced = true)
+            val tip = when (currentStatus) {
+                ScreenWhy.NotHave -> "快照成功 (无截图)"
+                ScreenWhy.Block -> "快照成功 (应用可能禁止截图)"
+                ScreenWhy.Pass -> "快照成功"
+            }
+            toast(tip, forced = true)
             val desc = snapshot.appInfo?.name ?: snapshot.appId
             snapshotNotif.copy(text = "快照「$desc」已保存至记录").notifySelf()
             return snapshot