Merge pull request #84 from ernestoyaquello/feature/82-global-layout-…

…memory-leak Fixed memory leak caused by global layout listener not being removed
ernestoyaquello · Jul 5, 2019 · 0945a8b · 0945a8b
2 parents f5699b6 + 5fa4834
commit 0945a8b
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Showing 2 changed files with 46 additions and 26 deletions.
diff --git a/build.gradle b/build.gradle
@@ -6,7 +6,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.4.0'
+        classpath 'com.android.tools.build:gradle:3.4.1'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:2.1'
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3'
     }

diff --git a/...r-form/src/main/java/ernestoyaquello/com/verticalstepperform/VerticalStepperFormView.java b/...r-form/src/main/java/ernestoyaquello/com/verticalstepperform/VerticalStepperFormView.java
@@ -32,7 +32,9 @@ public class VerticalStepperFormView extends LinearLayout {
     FormStyle style;
 
     private StepperFormListener listener;
+    private KeyboardTogglingObserver keyboardTogglingObserver;
     private List<StepHelper> stepHelpers;
+    private boolean initialized;
 
     private LinearLayout formContentView;
     private ScrollView stepsScrollView;
@@ -455,6 +457,8 @@ private void onConstructed(Context context, AttributeSet attrs, int defStyleAttr
         LayoutInflater inflater = LayoutInflater.from(context);
         inflater.inflate(R.layout.vertical_stepper_form_layout, this, true);
 
+        keyboardTogglingObserver = new KeyboardTogglingObserver();
+
         style = new FormStyle();
 
         // Set the default values for all the style properties
@@ -663,15 +667,14 @@ void initializeForm(StepperFormListener listener, StepHelper[] stepsArray) {
             hideBottomNavigation();
         }
 
-        keyboardIsOpen = isKeyboardOpen();
-        setObserverForKeyboard();
-
         for (int i = 0; i < stepHelpers.size(); i++) {
             View stepLayout = initializeStepHelper(i);
             formContentView.addView(stepLayout);
         }
 
         goToStep(0, false);
+
+        initialized = true;
     }
 
     private View initializeStepHelper(int position) {
@@ -765,28 +768,6 @@ private void enableOrDisableLastStepNextButton() {
         }
     }
 
-    private void setObserverForKeyboard() {
-        getRootView().getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
-            @Override
-            public void onGlobalLayout() {
-                boolean keyboardWasOpen = keyboardIsOpen;
-                keyboardIsOpen = isKeyboardOpen();
-                if (keyboardIsOpen != keyboardWasOpen) {
-                    scrollToOpenStepIfNecessary(true);
-                }
-            }
-        });
-    }
-
-    private boolean isKeyboardOpen() {
-        Rect r = new Rect();
-        formContentView.getWindowVisibleDisplayFrame(r);
-        int screenHeight = formContentView.getRootView().getHeight();
-        int keyboardHeight = screenHeight - r.bottom;
-
-        return keyboardHeight > screenHeight * 0.2;
-    }
-
     private synchronized void attemptToCompleteForm(boolean isCancellation) {
         if (formCompleted) {
             return;
@@ -857,6 +838,33 @@ public void onClick(View view) {
                 goToNextStep(true);
             }
         });
+
+        addObserverForKeyboard();
+    }
+
+    @Override
+    protected void onDetachedFromWindow() {
+        removeObserverForKeyboard();
+
+        super.onDetachedFromWindow();
+    }
+
+    private void addObserverForKeyboard() {
+        keyboardIsOpen = isKeyboardOpen();
+        getRootView().getViewTreeObserver().addOnGlobalLayoutListener(keyboardTogglingObserver);
+    }
+
+    private void removeObserverForKeyboard() {
+        getRootView().getViewTreeObserver().removeOnGlobalLayoutListener(keyboardTogglingObserver);
+    }
+
+    private boolean isKeyboardOpen() {
+        Rect r = new Rect();
+        formContentView.getWindowVisibleDisplayFrame(r);
+        int screenHeight = formContentView.getRootView().getHeight();
+        int keyboardHeight = screenHeight - r.bottom;
+
+        return keyboardHeight > screenHeight * 0.2;
     }
 
     private void restoreFromState(
@@ -1025,4 +1033,16 @@ class FormStyle {
         boolean allowStepOpeningOnHeaderClick;
         float alphaOfDisabledElements;
     }
+
+    private class KeyboardTogglingObserver implements ViewTreeObserver.OnGlobalLayoutListener {
+
+        @Override
+        public void onGlobalLayout() {
+            boolean keyboardWasOpen = keyboardIsOpen;
+            keyboardIsOpen = isKeyboardOpen();
+            if (initialized && keyboardIsOpen != keyboardWasOpen) {
+                scrollToOpenStepIfNecessary(true);
+            }
+        }
+    }
 }