Support for predictive back gesture

wasky · May 15, 2023 · 28e32d7 · 28e32d7
1 parent 2c35737
commit 28e32d7
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Showing 7 changed files with 53 additions and 19 deletions.
diff --git a/library/src/main/java/com/stephentuso/welcome/WelcomeActivity.java b/library/src/main/java/com/stephentuso/welcome/WelcomeActivity.java
@@ -6,6 +6,7 @@
 import android.view.View;
 import android.widget.FrameLayout;
 
+import androidx.activity.OnBackPressedCallback;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.fragment.app.Fragment;
@@ -128,9 +129,14 @@ public void onViewHidden() {
         responsiveItems.setup(configuration);
 
         viewPager.addOnPageChangeListener(responsiveItems);
+        viewPager.addOnPageChangeListener(onPageChangeListener);
         viewPager.setCurrentItem(configuration.firstPageIndex());
 
         responsiveItems.onPageSelected(viewPager.getCurrentItem());
+
+        WelcomeSharedPreferencesHelper.storeWelcomeCompleted(this, getKey());
+
+        getOnBackPressedDispatcher().addCallback(this, onBackPressedCallback);
     }
 
     @Override
@@ -206,25 +212,24 @@ protected void onButtonBarSecondPressed() {
      * unless the key is changed.
      */
     protected void completeWelcomeScreen() {
-        WelcomeSharedPreferencesHelper.storeWelcomeCompleted(this, getKey());
-        setWelcomeScreenResult(RESULT_OK);
+        //WelcomeSharedPreferencesHelper.storeWelcomeCompleted(this, getKey());
+        //setWelcomeScreenResult(RESULT_OK);
         finish();
-        if (configuration.getExitAnimation() != WelcomeConfiguration.NO_ANIMATION_SET)
+        /*if (configuration.getExitAnimation() != WelcomeConfiguration.NO_ANIMATION_SET) {
             overridePendingTransition(R.anim.wel_none, configuration.getExitAnimation());
+        }*/
     }
 
     /**
      * Closes the activity, doesn't save as completed.
      * A subsequent call to WelcomeScreenHelper.show() would show this again.
      */
     protected void cancelWelcomeScreen() {
-        setWelcomeScreenResult(RESULT_CANCELED);
+        //setWelcomeScreenResult(RESULT_CANCELED);
         finish();
     }
 
-    @Override
-    public void onBackPressed() {
-
+    private void handleBackPressed() {
         // Scroll to previous page and return if back button navigates
         if (configuration.getBackButtonNavigatesPages() && scrollToPreviousPage()) {
             return;
@@ -238,11 +243,16 @@ public void onBackPressed() {
 
     }
 
+    private boolean isOnBackPressedCallbackShouldBeEnabled() {
+        if (!configuration.getBackButtonNavigatesPages()) return false;
+        return canScrollToPreviousPage();
+    }
+
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
 
         if (configuration.getShowActionBarBackButton() && item.getItemId() == android.R.id.home) {
-            onBackPressed();
+            handleBackPressed();
             return true;
         }
 
@@ -261,6 +271,30 @@ private String getKey() {
 
     protected abstract WelcomeConfiguration configuration();
 
+    private final OnBackPressedCallback onBackPressedCallback = new OnBackPressedCallback(false) {
+        @Override
+        public void handleOnBackPressed() {
+            handleBackPressed();
+        }
+    };
+
+    private final ViewPager.OnPageChangeListener onPageChangeListener = new ViewPager.OnPageChangeListener() {
+
+        @Override
+        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+        }
+
+        @Override
+        public void onPageSelected(int position) {
+            onBackPressedCallback.setEnabled(isOnBackPressedCallbackShouldBeEnabled());
+        }
+
+        @Override
+        public void onPageScrollStateChanged(int state) {
+        }
+
+    };
+
     private class WelcomeFragmentPagerAdapter extends FragmentPagerAdapter {
 
         public WelcomeFragmentPagerAdapter(FragmentManager fm) {

diff --git a/library/src/main/java/com/stephentuso/welcome/WelcomeConfiguration.java b/library/src/main/java/com/stephentuso/welcome/WelcomeConfiguration.java
@@ -422,10 +422,10 @@ public Builder swipeToDismiss(boolean swipeToDismiss) {
          * @param canSkip True to allow skipping, false to disable it
          * @return this Builder object to allow method calls to be chained
          */
-        public Builder canSkip(boolean canSkip) {
+        /*public Builder canSkip(boolean canSkip) {
             this.canSkip = canSkip;
             return this;
-        }
+        }*/
 
         /**
          * Only applies if skipping is allowed. Sets whether or not the back button can skip the welcome screen.
@@ -434,10 +434,10 @@ public Builder canSkip(boolean canSkip) {
          * @param backButtonSkips True to allow the back button to skip the welcome screen, false to disable it
          * @return this Builder object to allow method calls to be chained
          */
-        public Builder backButtonSkips(boolean backButtonSkips) {
+        /*public Builder backButtonSkips(boolean backButtonSkips) {
             this.backButtonSkips = backButtonSkips;
             return this;
-        }
+        }*/
 
         /**
          * Set whether or not pressing the back button will move to the previous page in the welcome screen.
@@ -573,10 +573,10 @@ public Builder defaultDescriptionTypefacePath(String typefacePath) {
          * @param exitAnimationResId The resource id of the animation to use
          * @return this Builder object to allow method calls to be chained
          */
-        public Builder exitAnimation(@AnimRes int exitAnimationResId) {
+        /*public Builder exitAnimation(@AnimRes int exitAnimationResId) {
             this.exitAnimationResId = exitAnimationResId;
             return this;
-        }
+        }*/
 
         /**
          * Set the color to be used when no background color is specified for a page

diff --git a/sample/src/main/java/com/stephentuso/welcomeexample/ButtonBarSingleWelcomeActivity.java b/sample/src/main/java/com/stephentuso/welcomeexample/ButtonBarSingleWelcomeActivity.java
@@ -20,7 +20,7 @@ protected WelcomeConfiguration configuration() {
                 .defaultTitleTypefacePath("Roboto-Bold.ttf")
                 .defaultHeaderTypefacePath("Roboto-Bold.ttf")
                 .bottomLayout(WelcomeConfiguration.BottomLayout.BUTTON_BAR_SINGLE)
-                .exitAnimation(android.R.anim.fade_out)
+                // .exitAnimation(android.R.anim.fade_out)
                 .page(new TitlePage(R.drawable.ic_image_white, "Title Page"))
                 .page(new BasicPage(R.drawable.ic_image_white, "Basic Page", "A page with a title and description").background(R.color.purple_background))
                 .build();

diff --git a/sample/src/main/java/com/stephentuso/welcomeexample/ButtonBarWelcomeActivity.java b/sample/src/main/java/com/stephentuso/welcomeexample/ButtonBarWelcomeActivity.java
@@ -20,7 +20,7 @@ public class ButtonBarWelcomeActivity extends WelcomeActivity {
     @Override
     protected WelcomeConfiguration configuration() {
         return new WelcomeConfiguration.Builder(this)
-                .canSkip(false)
+                // .canSkip(false)
                 .backButtonNavigatesPages(false)
                 .defaultTitleTypefacePath("Roboto-Bold.ttf")
                 .defaultHeaderTypefacePath("Roboto-Bold.ttf")

diff --git a/sample/src/main/java/com/stephentuso/welcomeexample/LightWelcomeActivity.java b/sample/src/main/java/com/stephentuso/welcomeexample/LightWelcomeActivity.java
@@ -28,7 +28,7 @@ protected WelcomeConfiguration configuration() {
                         "All colors can be customized with styles")
                         .headerColorResource(this, R.color.colorAccent))
                 .swipeToDismiss(true)
-                .exitAnimation(android.R.anim.fade_out)
+                // .exitAnimation(android.R.anim.fade_out)
                 .build();
     }
 

diff --git a/sample/src/main/java/com/stephentuso/welcomeexample/NoSkipWelcomeActivity.java b/sample/src/main/java/com/stephentuso/welcomeexample/NoSkipWelcomeActivity.java
@@ -27,7 +27,7 @@ protected WelcomeConfiguration configuration() {
                 .page(new BasicPage(R.drawable.ic_check_white,
                         "Completion",
                         "RESULT_OK will only be returned after navigating all the way to the end"))
-                .canSkip(false)
+                // .canSkip(false)
                 .swipeToDismiss(true)
                 .build();
     }

diff --git a/sample/src/main/java/com/stephentuso/welcomeexample/SampleWelcomeActivity.java b/sample/src/main/java/com/stephentuso/welcomeexample/SampleWelcomeActivity.java
@@ -44,7 +44,7 @@ protected WelcomeConfiguration configuration() {
                 )
 
                 .swipeToDismiss(true)
-                .exitAnimation(android.R.anim.fade_out)
+                // .exitAnimation(android.R.anim.fade_out)
                 .build();
     }