hwc: Add binder interface to get the visibleRegion

- This binder interface can be used by clients to know the
  active visible region for a display(pri/ext/virt)
- When external orientation is used, return the destFrame of
  the FrameBuffer layer, as its the viewFrame

Change-Id: I7cfd149c76c16b9a3031103c89b1932d44bcbecd
diff --git a/libhwcomposer/hwc_fbupdate.cpp b/libhwcomposer/hwc_fbupdate.cpp
index 0ca5ad9..d601f8f 100644
--- a/libhwcomposer/hwc_fbupdate.cpp
+++ b/libhwcomposer/hwc_fbupdate.cpp
@@ -176,6 +176,8 @@
         }
         calcExtDisplayPosition(ctx, NULL, mDpy, sourceCrop, displayFrame,
                                    transform, orient);
+        //Store the displayFrame, will be used in getDisplayViewFrame
+        ctx->dpyAttr[mDpy].mDstRect = displayFrame;
         setMdpFlags(layer, mdpFlags, 0, transform);
         // For External use rotator if there is a rotation value set
         ret = preRotateExtDisplay(ctx, layer, info,
diff --git a/libhwcomposer/hwc_qclient.cpp b/libhwcomposer/hwc_qclient.cpp
index a3f6b5b..50e94c9 100644
--- a/libhwcomposer/hwc_qclient.cpp
+++ b/libhwcomposer/hwc_qclient.cpp
@@ -140,8 +140,34 @@
     ctx->mBufferMirrorMode = enable;
 }
 
+static status_t getDisplayVisibleRegion(hwc_context_t* ctx, int dpy,
+                                Parcel* outParcel) {
+    // Get the info only if the dpy is valid
+    if(dpy >= HWC_DISPLAY_PRIMARY && dpy <= HWC_DISPLAY_VIRTUAL) {
+        Locker::Autolock _sl(ctx->mDrawLock);
+        if(dpy && (ctx->mExtOrientation || ctx->mBufferMirrorMode)) {
+            // Return the destRect on external, if external orienation
+            // is enabled
+            outParcel->writeInt32(ctx->dpyAttr[dpy].mDstRect.left);
+            outParcel->writeInt32(ctx->dpyAttr[dpy].mDstRect.top);
+            outParcel->writeInt32(ctx->dpyAttr[dpy].mDstRect.right);
+            outParcel->writeInt32(ctx->dpyAttr[dpy].mDstRect.bottom);
+        } else {
+            outParcel->writeInt32(ctx->mViewFrame[dpy].left);
+            outParcel->writeInt32(ctx->mViewFrame[dpy].top);
+            outParcel->writeInt32(ctx->mViewFrame[dpy].right);
+            outParcel->writeInt32(ctx->mViewFrame[dpy].bottom);
+        }
+        return NO_ERROR;
+    } else {
+        ALOGE("In %s: invalid dpy index %d", __FUNCTION__, dpy);
+        return BAD_VALUE;
+    }
+}
+
 status_t QClient::notifyCallback(uint32_t command, const Parcel* inParcel,
         Parcel* outParcel) {
+    status_t ret = NO_ERROR;
 
     if (command > IQService::VPU_COMMAND_LIST_START &&
         command < IQService::VPU_COMMAND_LIST_END) {
@@ -164,6 +190,10 @@
         case IQService::BUFFER_MIRRORMODE:
             setBufferMirrorMode(mHwcContext, inParcel->readInt32());
             break;
+        case IQService::GET_DISPLAY_VISIBLE_REGION:
+            ret = getDisplayVisibleRegion(mHwcContext, inParcel->readInt32(),
+                                    outParcel);
+            break;
         case IQService::CHECK_EXTERNAL_STATUS:
             isExternalConnected(mHwcContext, outParcel);
             break;
@@ -174,9 +204,9 @@
             setHSIC(mHwcContext, inParcel);
             break;
         default:
-            return NO_ERROR;
+            ret = NO_ERROR;
     }
-    return NO_ERROR;
+    return ret;
 }
 
 
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index 872b306..cd84f73 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -87,6 +87,8 @@
     bool isConfiguring;
     // External Display is in MDP Downscale mode indicator
     bool mDownScaleMode;
+    // Ext dst Rect
+    hwc_rect_t mDstRect;
 };
 
 struct ListStats {