1 files changed, 105 insertions, 0 deletions
diff --git a/libs/thedevstacklogcat/src/main/java/de/thedevstack/android/logcat/tasks/ReadLogCatAsyncTask.java b/libs/thedevstacklogcat/src/main/java/de/thedevstack/android/logcat/tasks/ReadLogCatAsyncTask.java
new file mode 100644
index 00000000..1136faf8
--- /dev/null
+++ b/libs/thedevstacklogcat/src/main/java/de/thedevstack/android/logcat/tasks/ReadLogCatAsyncTask.java
@@ -0,0 +1,105 @@
+package de.thedevstack.android.logcat.tasks;
+
+import android.os.AsyncTask;
+import android.widget.ArrayAdapter;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+import de.thedevstack.android.logcat.Logging;
+
+/**
+ * Task to read the logcat of the App.
+ * The command <code>logcat -d -v time</code> is used to load the logs.
+ * This reader uses a white list to restrict the messages to display, otherwise it might be flooded with useless log messages.
+ * The white list checks if a log messages contains one of the following strings:
+ * <ul>
+ *     <li>{@value Logging#LOG_TAG_PREFIX}</li>
+ *     <li><code>E/</code> - for every error message</li>
+ *     <li><code>W/</code> - for every warning message</li>
+ * </ul>
+ */
+public class ReadLogCatAsyncTask extends AsyncTask<Void, Void, String[]> {
+    /**
+     * The array adapter to publish the log messages to.
+     */
+    private final ArrayAdapter<String> arrayAdapter;
+    /**
+     * The command to execute logcat.
+     */
+    private static final String[] LOG_CAT_CMD = { "logcat", "-d", "-v", "time"};
+    /**
+     * The white list to filter log messages.
+     */
+    private static final String[] WHITE_LIST = { Logging.getLogTagPrefix(), "E/", "W/" };
+
+    /**
+     * Initializes the Task with the array adapter to publish the log messages to.
+     * @param arrayAdapter the array adapter
+     */
+    public ReadLogCatAsyncTask(ArrayAdapter<String> arrayAdapter) {
+        this.arrayAdapter = arrayAdapter;
+    }
+
+    /**
+     * Executes the logcat command, reads the output of the command and returns all log messages.
+     * @param params no params will be passed. (interface compliance)
+     * @return the array of log messages
+     */
+    @Override
+    protected String[] doInBackground(Void... params) {
+        ArrayList<String> logCatOutput = new ArrayList<>();
+        BufferedReader bufferedReader = null;
+        try {
+            Process process = Runtime.getRuntime().exec(ReadLogCatAsyncTask.LOG_CAT_CMD);
+            bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
+            String line = "";
+            while ((line = bufferedReader.readLine()) != null) {
+                logCatOutput.add(line);
+            }
+        } catch (IOException e) {
+            Logging.e("ReadLogCat", "error while retrieving information from logcat: " + e.getMessage(), e);
+        } finally {
+            if (null != bufferedReader) {
+                try {
+                    bufferedReader.close();
+                } catch (IOException e) {
+                }
+            }
+        }
+        logCatOutput.trimToSize();
+        return logCatOutput.toArray(new String[0]);
+    }
+
+    /**
+     * Clears the array adapter and adds the filtered log messages.
+     * @param items all log messages
+     */
+    @Override
+    protected void onPostExecute(String[] items) {
+        this.arrayAdapter.clear();
+        if (null != items && items.length > 0) {
+            for (String item : items) {
+                if (!filter(item)) {
+                    this.arrayAdapter.add(item);
+                }
+            }
+        }
+    }
+
+    /**
+     * Checks whether a log message contains a white listed string or not.
+     * @param item the item to filter
+     * @return <code>true</code> if the string should be filtered (removed from the list) <code>false</code> otherwise.
+     */
+    protected boolean filter(String item) {
+        for (String whiteListed : ReadLogCatAsyncTask.WHITE_LIST) {
+            if (item.contains(whiteListed)) {
+                return false;
+            }
+        }
+        return true;
+    }
+}