Settings: Show full proc/version information

patch set 2: view unformatted kernel version on clicking
  the formatted kernel version

[ Stallix - Evo X ]

* Adapted for KernelVersionPreferenceController on Pie

Change-Id: I2b211fb72c25cc119f2a464b04821fcef77a8908
Signed-off-by: Arghya Chanda <arghyac35@gmail.com>
Signed-off-by: SagarMakhar <sagarmakhar@gmail.com>
Signed-off-by: Joey Huab <joey@evolution-x.org>
Signed-off-by: AnierinB <anierin@evolution-x.org>

res/xml/firmware_version.xml

@@ -84,7 +84,6 @@
         android:key="kernel_version"
         android:title="@string/kernel_version"
         android:summary="@string/summary_placeholder"
-        android:selectable="false"
         settings:enableCopying="true"
         settings:controller="com.android.settings.deviceinfo.firmwareversion.KernelVersionPreferenceController"/>
 

src/com/android/settings/deviceinfo/firmwareversion/KernelVersionPreferenceController.java

@@ -20,10 +20,21 @@ import android.content.Context;
 
 import com.android.settings.core.BasePreferenceController;
 import com.android.settingslib.DeviceInfoUtils;
+import androidx.preference.Preference;
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
 
 // LINT.IfChange
 public class KernelVersionPreferenceController extends BasePreferenceController {
 
+    private static final String KEY_KERNEL_VERSION = "kernel_version";
+    private static final String FILENAME_PROC_VERSION = "/proc/version";
+    private static final String LOG_TAG = "KernelVersionPreferenceController";
+
     public KernelVersionPreferenceController(Context context, String preferenceKey) {
         super(context, preferenceKey);
     }
@@ -37,5 +48,46 @@ public class KernelVersionPreferenceController extends BasePreferenceController
     public CharSequence getSummary() {
         return DeviceInfoUtils.getFormattedKernelVersion(mContext);
     }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_KERNEL_VERSION;
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        if (!TextUtils.equals(preference.getKey(), KEY_KERNEL_VERSION)) {
+            return false;
+        }
+        preference.setSummary(getFullKernelVersion());
+        return false;
+    }
+
+    private String getFullKernelVersion() {
+        String procVersionStr;
+        try {
+            procVersionStr = readLine(FILENAME_PROC_VERSION);
+            return procVersionStr;
+        } catch (IOException e) {
+            Log.e(LOG_TAG,
+            "IO Exception when getting kernel version for Device Info screen", e);
+            return "Unavailable";
+        }
+    }
+
+    /**
+     * Reads a line from the specified file.
+     * @param filename the file to read from
+     * @return the first line, if any.
+     * @throws IOException if the file couldn't be read
+     */
+    private static String readLine(String filename) throws IOException {
+        BufferedReader reader = new BufferedReader(new FileReader(filename), 256);
+        try {
+            return reader.readLine();
+        } finally {
+            reader.close();
+        }
+    }
 }
 // LINT.ThenChange(KernelVersionPreference.kt)