[Galaxy S6 General] asc1977:
How to center clock which disappear on lockscreen

work also with Potatoe clock. that was the main reason why i did

decompile SystemUI.apk

open res/values/ids.xml and add followed at the end

<item type="id" name="system_icon_area2">false</item>

Now recompile and decompile the recompiled SystemUI.apk to get the id

open res/layout/status_bar.xml

remove red and add blue

<?xml version="1.0" encoding="utf-8"?>
<com.android.systemui.statusbar.phone.PhoneStatusBarView android:orientation="vertical" android:id="@id/status_bar" android:background="#00000000" android:focusable="true" android:descendantFocusability="afterDescendants"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:systemui="http://schemas.android.com/apk/res/com.android.systemui">
<potato.mariozawa.statusbargradient.Gradient android:gravity="center" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent" />
<FrameLayout android:id="@id/call_background" android:background="@color/call_background_idle_color" android:layout_width="fill_parent" android:layout_height="fill_parent" />
<ImageView android:id="@id/notification_lights_out" android:paddingBottom="2.0dip" android:visibility="gone" android:layout_width="@dimen/status_bar_icon_size" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_lights_out_dot_small" android:scaleType="center" android:paddingStart="1.0dip" />
<LinearLayout android:orientation="horizontal" android:id="@id/status_bar_contents" android:layout_width="fill_parent" android:layout_height="fill_parent" android:paddingStart="1.0dip" android:paddingEnd="1.0dip">
<com.android.systemui.statusbar.AlphaOptimizedFrameLayout android:orientation="horizontal" android:id="@id/notification_icon_area" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0">
<com.android.keyguard.AlphaOptimizedLinearLayout android:id="@id/notification_icon_area_inner" android:layout_width="fill_parent" android:layout_height="fill_parent">
<com.android.systemui.statusbar.StatusBarIconView android:id="@id/moreIcon" android:visibility="gone" android:layout_width="@dimen/status_bar_icon_size" android:layout_height="fill_parent" android:src="@drawable/stat_notify_more" />
<com.android.systemui.statusbar.phone.IconMerger android:gravity="center_vertical" android:orientation="horizontal" android:id="@id/notificationIcons" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_alignParentStart="true" />
</com.android.keyguard.AlphaOptimizedLinearLayout>
</com.android.systemui.statusbar.AlphaOptimizedFrameLayout>
[COLOR="Red"] <com.android.keyguard.AlphaOptimizedLinearLayout android:orientation="horizontal" android:id="@id/system_icon_area" android:layout_width="wrap_content" android:layout_height="fill_parent">
<TextView android:textSize="12.0dip" android:textColor="#ffffffff" android:gravity="center_vertical" android:id="@id/knoxCustomStatusBarText" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="fill_parent" android:includeFontPadding="false" />
<include layout="@layout/system_icons" />
<com.android.systemui.statusbar.policy.Clock android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="start|center" android:id="@id/clock" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:paddingStart="1.0dip" />
</com.android.keyguard.AlphaOptimizedLinearLayout>
</LinearLayout>
</com.android.systemui.statusbar.phone.PhoneStatusBarView>
[COLOR="RoyalBlue"] <com.android.keyguard.AlphaOptimizedLinearLayout android:id="@id/system_icon_area" android:layout_width="wrap_content" android:layout_height="fill_parent">
<com.android.systemui.statusbar.policy.Clock android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="start|center" android:id="@id/clock" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:paddingStart="1.0dip" />
</com.android.keyguard.AlphaOptimizedLinearLayout>
<LinearLayout android:gravity="center|right" android:orientation="horizontal" android:id="@id/system_icon_area2" android:layout_width="0.0dip" android:layout_height="fill_parent" android:layout_weight="1.0" android:layout_alignParentRight="true" android:alpha="1.0">
<com.android.keyguard.AlphaOptimizedLinearLayout android:orientation="horizontal" android:layout_width="wrap_content" android:layout_height="fill_parent">
<TextView android:textSize="12.0dip" android:textColor="#ffffffff" android:gravity="center_vertical" android:id="@id/knoxCustomStatusBarText" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="fill_parent" android:includeFontPadding="false" />
<include layout="@layout/system_icons" />
</com.android.keyguard.AlphaOptimizedLinearLayout>
</LinearLayout>
</LinearLayout>[/COLOR][/COLOR]

open smali/com/android/systemui/statusbar/phone/StatusBarIconController.smali

find and add blue

.field private mSystemIconArea:Landroid/widget/LinearLayout;

[COLOR="Blue"].field private mSystemIconArea2:Landroid/widget/LinearLayout;[/COLOR]

find and add blue and replace id with yours from public.xml

.line 171
const v1, 0x7f0e02eb

invoke-virtual {p2, v1}, Landroid/view/View;->findViewById(I)Landroid/view/View;

move-result-object v1

check-cast v1, Landroid/widget/LinearLayout;

iput-object v1, p0, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->mSystemIconArea:Landroid/widget/LinearLayout;

[COLOR="blue"]const v1, 0x7f0e0379 [B]#<public type="id" name="system_icon_area2" id="0x7f0e0379" />[/B]

invoke-virtual {p2, v1}, Landroid/view/View;->findViewById(I)Landroid/view/View;

move-result-object v1

check-cast v1, Landroid/widget/LinearLayout;

iput-object v1, p0, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->mSystemIconArea2:Landroid/widget/LinearLayout;[/COLOR]

find and add in blue

.method public hideSystemIconArea(Z)V
.locals 1
.param p1, "animate" # Z

.prologue
.line 370
iget-object v0, p0, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->mSystemIconArea:Landroid/widget/LinearLayout;

invoke-direct {p0, v0, p1}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->animateHide(Landroid/view/View;Z)V

.line 371
return-void
.end method

[COLOR="blue"].method public hideSystemIconArea2(Z)V
.locals 1
.param p1, "animate" # Z

.prologue
.line 370
iget-object v0, p0, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->mSystemIconArea2:Landroid/widget/LinearLayout;

invoke-direct {p0, v0, p1}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->animateHide(Landroid/view/View;Z)V

.line 371
return-void
.end method[/COLOR]

find and add in blue

.method public showSystemIconArea(Z)V
.locals 1
.param p1, "animate" # Z

.prologue
.line 374
iget-object v0, p0, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->mSystemIconArea:Landroid/widget/LinearLayout;

invoke-direct {p0, v0, p1}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->animateShow(Landroid/view/View;Z)V

.line 375
return-void
.end method

[COLOR="blue"].method public showSystemIconArea2(Z)V
.locals 1
.param p1, "animate" # Z

.prologue
.line 374
iget-object v0, p0, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->mSystemIconArea2:Landroid/widget/LinearLayout;

invoke-direct {p0, v0, p1}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->animateShow(Landroid/view/View;Z)V

.line 375
return-void
.end method[/COLOR]

open smali/com/android/systemui/statusbar/phone/PhoneStatusBar.smali

find and add blue

invoke-virtual {v7, v8}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->hideSystemIconArea(Z)V

[COLOR="blue"]invoke-virtual {v7, v8}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->hideSystemIconArea2(Z)V[/COLOR]

find and add blue

invoke-virtual {v7, p3}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->showSystemIconArea(Z)V

[COLOR="blue"]invoke-virtual {v7, p3}, Lcom/android/systemui/statusbar/phone/StatusBarIconController;->showSystemIconArea2(Z)V[/COLOR]

recompile and finished

The smali edits are nessesary because if you didnt do you have two signal icons on lockscreen means one on top of other

Credits to nobody because its my work. if you find guide anywhere else i am sorry but i didnt know.

ITS NOT REWRITTEN !!!