1 files changed, 90 insertions, 0 deletions
diff --git a/ui/window/MultiWindowPlayground/kotlinApp/Application/src/main/java/com/android/multiwindowplayground/logger/LogView.kt b/ui/window/MultiWindowPlayground/kotlinApp/Application/src/main/java/com/android/multiwindowplayground/logger/LogView.kt
new file mode 100755
index 00000000..22488dce
--- /dev/null
+++ b/ui/window/MultiWindowPlayground/kotlinApp/Application/src/main/java/com/android/multiwindowplayground/logger/LogView.kt
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2017 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 com.android.multiwindowplayground.logger
+
+import android.app.Activity
+import android.content.Context
+
+/**
+ * Simple TextView which is used to output log data received through the LogNode interface.
+ */
+class LogView(context: Context) : android.support.v7.widget.AppCompatTextView(context), LogNode {
+
+    // The next LogNode in the chain.
+    private var next: LogNode? = null
+
+    /**
+     * Formats the log data and prints it out to the LogView.
+     *
+     * @param priority Log level of the data being logged.  Verbose, Error, etc.
+     * @param tag      Tag for for the log data.  Can be used to organize log statements.
+     * @param msg      The actual message to be logged. The actual message to be logged.
+     * @param tr       If an exception was thrown, this can be sent along for the logging
+     *                 facilities to extract and print useful information.
+     */
+    override fun println(priority: Int, tag: String?, msg: String, tr: Throwable?) {
+
+        // For the purposes of this View, we want to print the priority as readable text.
+        val priorityStr = when (priority) {
+            android.util.Log.VERBOSE -> "VERBOSE"
+            android.util.Log.DEBUG -> "DEBUG"
+            android.util.Log.INFO -> "INFO"
+            android.util.Log.WARN -> "WARN"
+            android.util.Log.ERROR -> "ERROR"
+            android.util.Log.ASSERT -> "ASSERT"
+            else -> "VERBOSE"
+        }
+
+        // Handily, the Log class has a facility for converting a stack trace into a usable string.
+        var exceptionStr: String? = null
+        if (tr != null) exceptionStr = android.util.Log.getStackTraceString(tr)
+
+        // Take the priority, tag, message, and exception, and concatenate as necessary
+        // into one usable line of text.
+        val delimiter = "\t"
+        val outputBuilder = StringBuilder().also {
+            appendIfNotNullOrEmpty(it, priorityStr, delimiter)
+            appendIfNotNullOrEmpty(it, tag, delimiter)
+            appendIfNotNullOrEmpty(it, msg, delimiter)
+            appendIfNotNullOrEmpty(it, exceptionStr, delimiter)
+        }
+
+        // In case this was originally called from an AsyncTask or some other off-UI thread,
+        // make sure the update occurs within the UI thread.
+        (context as Activity).runOnUiThread(Thread(Runnable {
+            // Display the text we just generated within the LogView as a new line of log data.
+            append("\n$outputBuilder")
+        }))
+
+        next?.println(priority, tag, msg, tr)
+    }
+
+    /**
+     * Takes a string and adds to it, with a separator, if the bit to be added isn't null. Since
+     * the logger takes so many arguments that might be null, this method helps cut out some of the
+     * agonizing tedium of writing the same statement over and over.
+     *
+     * @param source    StringBuilder containing the text to append to.
+     * @param addStr    The String to append
+     * @param delimiter The String to separate the source and appended strings.
+     */
+    private fun appendIfNotNullOrEmpty(source: StringBuilder, addStr: String?, delimiter: String) {
+        if (addStr.isNullOrEmpty()) return
+        source.append(addStr).append(delimiter)
+    }
+
+}