Merge "Make Verification text shrink to zero size for long names or large fonts." into sc-dev
diff --git a/core/java/com/android/internal/widget/ConversationHeaderLinearLayout.java b/core/java/com/android/internal/widget/ConversationHeaderLinearLayout.java
new file mode 100644
index 0000000..481183e
--- /dev/null
+++ b/core/java/com/android/internal/widget/ConversationHeaderLinearLayout.java
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2021 The Android Open Source 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.internal.widget;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.LinearLayout;
+import android.widget.RemoteViews;
+
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * This is a subclass of LinearLayout meant to be used in the Conversation header, to fix a bug
+ * when multiple user-provided strings are shown in the same conversation header.  b/189723284
+ *
+ * This works around a deficiency in LinearLayout when shrinking views that it can't fully reduce
+ * all contents if any of the oversized views reaches zero.
+ */
+@RemoteViews.RemoteView
+public class ConversationHeaderLinearLayout extends LinearLayout {
+
+    public ConversationHeaderLinearLayout(Context context) {
+        super(context);
+    }
+
+    public ConversationHeaderLinearLayout(Context context,
+            @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public ConversationHeaderLinearLayout(Context context, @Nullable AttributeSet attrs,
+            int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    private int calculateTotalChildLength() {
+        final int count = getChildCount();
+        int totalLength = 0;
+
+        for (int i = 0; i < count; ++i) {
+            final View child = getChildAt(i);
+            if (child == null || child.getVisibility() == GONE) {
+                continue;
+            }
+            final LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams)
+                    child.getLayoutParams();
+            totalLength += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
+        }
+        return totalLength + getPaddingLeft() + getPaddingRight();
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+
+        final int containerWidth = getMeasuredWidth();
+        final int contentsWidth = calculateTotalChildLength();
+
+        int excessContents = contentsWidth - containerWidth;
+        if (excessContents <= 0) {
+            return;
+        }
+        final int count = getChildCount();
+
+        float remainingWeight = 0;
+        List<ViewInfo> visibleChildrenToShorten = null;
+
+        // Find children which need to be shortened in order to ensure the contents fit.
+        for (int i = 0; i < count; ++i) {
+            final View child = getChildAt(i);
+            if (child == null || child.getVisibility() == View.GONE) {
+                continue;
+            }
+            final float weight = ((LayoutParams) child.getLayoutParams()).weight;
+            if (weight == 0) {
+                continue;
+            }
+            if (child.getMeasuredWidth() == 0) {
+                continue;
+            }
+            if (visibleChildrenToShorten == null) {
+                visibleChildrenToShorten = new LinkedList<>();
+            }
+            visibleChildrenToShorten.add(new ViewInfo(child));
+            remainingWeight += Math.max(0, weight);
+        }
+        if (visibleChildrenToShorten == null || visibleChildrenToShorten.isEmpty()) {
+            return;
+        }
+        balanceViewWidths(visibleChildrenToShorten, remainingWeight, excessContents);
+        remeasureChangedChildren(visibleChildrenToShorten);
+    }
+
+    /**
+     * Measure any child with a width that has changed.
+     */
+    private void remeasureChangedChildren(List<ViewInfo> childrenInfo) {
+        for (ViewInfo info : childrenInfo) {
+            if (info.mWidth != info.mStartWidth) {
+                final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
+                        Math.max(0, info.mWidth), MeasureSpec.EXACTLY);
+                final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
+                        info.mView.getMeasuredHeight(), MeasureSpec.EXACTLY);
+                info.mView.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+            }
+        }
+    }
+
+    /**
+     * Given a list of view, use the weights to remove width from each view proportionally to the
+     * weight (and ignoring the view's actual width), but do this iteratively whenever a view is
+     * reduced to zero width, because in that case other views need reduction.
+     */
+    void balanceViewWidths(List<ViewInfo> viewInfos, float weightSum, int excessContents) {
+        boolean performAnotherPass = true;
+        // Loops only when all of the following are true:
+        // * `performAnotherPass` -- a view clamped to 0 width (or the first iteration)
+        // * `excessContents > 0` -- there is still horizontal space to allocate
+        // * `weightSum > 0` -- at least 1 view with nonzero width AND nonzero weight left
+        while (performAnotherPass && excessContents > 0 && weightSum > 0) {
+            int excessRemovedDuringThisPass = 0;
+            float weightSumForNextPass = 0;
+            performAnotherPass = false;
+            for (ViewInfo info : viewInfos) {
+                if (info.mWeight <= 0) {
+                    continue;
+                }
+                if (info.mWidth <= 0) {
+                    continue;
+                }
+                int newWidth = (int) (info.mWidth - (excessContents * (info.mWeight / weightSum)));
+                if (newWidth < 0) {
+                    newWidth = 0;
+                    performAnotherPass = true;
+                }
+                excessRemovedDuringThisPass += info.mWidth - newWidth;
+                info.mWidth = newWidth;
+                if (info.mWidth > 0) {
+                    weightSumForNextPass += info.mWeight;
+                }
+            }
+            excessContents -= excessRemovedDuringThisPass;
+            weightSum = weightSumForNextPass;
+        }
+    }
+
+    /**
+     * A helper class for measuring children.
+     */
+    static class ViewInfo {
+        final View mView;
+        final float mWeight;
+        final int mStartWidth;
+        int mWidth;
+
+        ViewInfo(View view) {
+            this.mView = view;
+            this.mWeight = ((LayoutParams) view.getLayoutParams()).weight;
+            this.mStartWidth = this.mWidth = view.getMeasuredWidth();
+        }
+    }
+}
diff --git a/core/res/res/layout/notification_template_conversation_header.xml b/core/res/res/layout/notification_template_conversation_header.xml
index 389637eb..2faff41 100644
--- a/core/res/res/layout/notification_template_conversation_header.xml
+++ b/core/res/res/layout/notification_template_conversation_header.xml
@@ -14,7 +14,7 @@
   ~ See the License for the specific language governing permissions and
   ~ limitations under the License
   -->
-<LinearLayout
+<com.android.internal.widget.ConversationHeaderLinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/conversation_header"
     android:layout_width="wrap_content"
@@ -119,6 +119,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="@dimen/notification_conversation_header_separating_margin"
+        android:layout_weight="100"
         android:showRelative="true"
         android:singleLine="true"
         android:visibility="gone"
@@ -171,4 +172,4 @@
         android:src="@drawable/ic_notifications_alerted"
         android:visibility="gone"
         />
-</LinearLayout>
+</com.android.internal.widget.ConversationHeaderLinearLayout>