From be136b9c5cedfb018b5a05fecac5ea9a3e242f36 Mon Sep 17 00:00:00 2001
From: Wilson Filho <will.flho@gmail.com>
Date: Mon, 24 May 2021 17:59:55 -0300
Subject: [PATCH] feat: adds maxHeight to bottom sheet behavior

---
 .../bottomsheet/BottomSheetBehavior.java      | 44 +++++++++++++++++++
 .../material/bottomsheet/res/values/attrs.xml |  1 +
 2 files changed, 45 insertions(+)

diff --git a/lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java b/lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java
index a84c549d029..267787d2fbb 100644
--- a/lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java
+++ b/lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java
@@ -197,6 +197,8 @@ public abstract static class BottomSheetCallback {
 
   private static final int NO_WIDTH = -1;
 
+  private static final int NO_HEIGHT = -1;
+
   private boolean fitToContents = true;
 
   private boolean updateImportantForAccessibilityOnSiblings = false;
@@ -222,6 +224,8 @@ public abstract static class BottomSheetCallback {
 
   private int maxWidth = NO_WIDTH;
 
+  private int maxHeight = NO_HEIGHT;
+
   private int gestureInsetBottom;
   private boolean gestureInsetBottomIgnored;
   private boolean paddingBottomSystemWindowInsets;
@@ -324,6 +328,12 @@ public BottomSheetBehavior(@NonNull Context context, @Nullable AttributeSet attr
               R.styleable.BottomSheetBehavior_Layout_android_maxWidth, NO_WIDTH));
     }
 
+    if (a.hasValue(R.styleable.BottomSheetBehavior_Layout_android_maxHeight)) {
+      setMaxHeight(
+          a.getDimensionPixelSize(
+              R.styleable.BottomSheetBehavior_Layout_android_maxHeight, NO_HEIGHT));
+    }
+
     TypedValue value = a.peekValue(R.styleable.BottomSheetBehavior_Layout_behavior_peekHeight);
     if (value != null && value.data == PEEK_HEIGHT_AUTO) {
       setPeekHeight(value.data);
@@ -453,6 +463,18 @@ public void run() {
           }
         });
       }
+
+      int height = child.getMeasuredHeight();
+      if (height > maxHeight && maxHeight != NO_HEIGHT) {
+        final ViewGroup.LayoutParams lp = child.getLayoutParams();
+        lp.height = maxHeight;
+        child.post(new Runnable() {
+          @Override
+          public void run() {
+            child.setLayoutParams(lp);
+          }
+        });
+      }
     }
     if (viewDragHelper == null) {
       viewDragHelper = ViewDragHelper.create(parent, dragCallback);
@@ -829,6 +851,28 @@ public int getMaxWidth() {
     return maxWidth;
   }
 
+  /**
+   * Sets the maximum height of the bottom sheet.
+   * This method should be called before {@link BottomSheetDialog#show()} in order for the height to
+   * be adjusted as expected.
+   *
+   * @param maxHeight The maximum height in pixels to be set
+   * @attr ref com.google.android.material.R.styleable#BottomSheetBehavior_Layout_android_maxHeight
+   * @see #getMaxHeight()
+   */
+  public void setMaxHeight(@Px int maxHeight) {
+    this.maxHeight = maxHeight;
+  }
+
+  /**
+   * Returns the bottom sheet's maximum height, or -1 if no maximum height is set.
+   *
+   * @attr ref com.google.android.material.R.styleable#BottomSheetBehavior_Layout_android_maxHeight
+   * @see #setMaxHeight(int)
+   */
+  @Px
+  public int getMaxHeight() { return maxHeight; }
+
   /**
    * Sets the height of the bottom sheet when it is collapsed.
    *
diff --git a/lib/java/com/google/android/material/bottomsheet/res/values/attrs.xml b/lib/java/com/google/android/material/bottomsheet/res/values/attrs.xml
index 9652afe6645..729f0e5ba9e 100644
--- a/lib/java/com/google/android/material/bottomsheet/res/values/attrs.xml
+++ b/lib/java/com/google/android/material/bottomsheet/res/values/attrs.xml
@@ -83,6 +83,7 @@
     <attr name="paddingTopSystemWindowInsets" />
     <attr name="android:elevation"/>
     <attr name="android:maxWidth"/>
+    <attr name="android:maxHeight"/>
 
   </declare-styleable>