1 files changed, 72 insertions, 0 deletions
diff --git a/services/java/com/android/server/power/AutoBrightnessHandler.java b/services/java/com/android/server/power/AutoBrightnessHandler.java
new file mode 100644
index 0000000..c077317
--- /dev/null
+++ b/services/java/com/android/server/power/AutoBrightnessHandler.java
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+/*
+ * Copyright (C) 2013 The CyanogenMod 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.server.power;
+
+import android.content.Context;
+import android.os.SystemProperties;
+import android.provider.Settings;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+/**
+ * Certain display devices require that we set a special mode when enabling auto-brightness.
+ * This is done by setting a sysfs node. This behavior can be configured by setting the
+ * config_panelAutoBrightnessValue to the integer value to write when enabled.
+ *
+ * Some high-end panels might support alternative brightness modes such as high gamma. This
+ * is highly device-specific, but we will support these via a persistent system property.
+ *
+ * @hide
+ */
+public class AutoBrightnessHandler {
+
+    private static final String NODE = "/sys/class/lcd/panel/panel/auto_brightness";
+
+    private static final String ALT_BRIGHTNESS_PROP = "persist.sys.alt.brightness";
+
+    private static final int PANEL_MANUAL = 0;
+
+    private final int mPanelAutoValue;
+
+    public AutoBrightnessHandler(Context context) {
+        mPanelAutoValue = context.getResources().getInteger(
+                com.android.internal.R.integer.config_panelAutoBrightnessValue);
+    }
+
+    public void onAutoBrightnessChanged(int mode) {
+        if (mPanelAutoValue > -1) {
+            int override = SystemProperties.getInt(ALT_BRIGHTNESS_PROP, -1);
+            writeValue(NODE, mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC ?
+                    (override > -1 ? override : mPanelAutoValue) : PANEL_MANUAL);
+        }
+    }
+
+    private static void writeValue(String filename, int value) {
+        try {
+            FileOutputStream fos = new FileOutputStream(new File(filename));
+            fos.write(String.valueOf(value).getBytes());
+            fos.flush();
+            fos.close();
+        } catch (FileNotFoundException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}