Allow tapping on the edges of the chapter to change pages

2025-11-18 15:07:30 +01:00 · 2015-10-22 02:20:42 +02:00
parent 38c6fac385
commit 3a748a9453
4 changed files with 173 additions and 16 deletions
--- a/app/src/main/java/eu/kanade/mangafeed/widget/ReaderViewPager.java
+++ b/app/src/main/java/eu/kanade/mangafeed/widget/ReaderViewPager.java
@@ -0,0 +1,135 @@
+package eu.kanade.mangafeed.widget;
+
+import android.content.Context;
+import android.support.v4.view.ViewPager;
+import android.util.AttributeSet;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+
+public class ReaderViewPager extends ViewPager {
+
+    private GestureDetector gestureDetector;
+
+    private OnChapterBoundariesOutListener mOnChapterBoundariesOutListener;
+    private OnChapterSingleTapListener mOnChapterSingleTapListener;
+
+    private static final float LEFT_REGION = 0.33f;
+    private static final float RIGHT_REGION = 0.66f;
+    private static final float SWIPE_TOLERANCE = 0.25f;
+    private float startDragX;
+
+    public ReaderViewPager(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        gestureDetector = new GestureDetector(getContext(), new ReaderViewGestureListener());
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        try {
+            gestureDetector.onTouchEvent(ev);
+
+            if ((ev.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
+                if (this.getCurrentItem() == 0 || this.getCurrentItem() == this.getAdapter().getCount() - 1) {
+                    startDragX = ev.getX();
+                }
+            }
+
+            return super.onInterceptTouchEvent(ev);
+        } catch (IllegalArgumentException e) {
+            // Do Nothing.
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent ev) {
+        try {
+            if (mOnChapterBoundariesOutListener != null) {
+                if (this.getCurrentItem() == 0) {
+                    if ((ev.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_UP) {
+                        float displacement = ev.getX() - startDragX;
+
+                        if (ev.getX() > startDragX && displacement > getWidth() * SWIPE_TOLERANCE) {
+                            mOnChapterBoundariesOutListener.onFirstPageOut();
+                            return true;
+                        }
+
+                        startDragX = 0;
+                    }
+                } else if (this.getCurrentItem() == this.getAdapter().getCount() - 1) {
+                    if ((ev.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_UP) {
+                        float displacement = startDragX - ev.getX();
+
+                        if (ev.getX() < startDragX && displacement > getWidth() * SWIPE_TOLERANCE) {
+                            mOnChapterBoundariesOutListener.onLastPageOut();
+                            return true;
+                        }
+
+                        startDragX = 0;
+                    }
+                }
+            }
+
+            return super.onTouchEvent(ev);
+        } catch (IllegalArgumentException e) {
+            // Do Nothing.
+        }
+
+        return false;
+    }
+
+    public boolean onImageTouch(MotionEvent event) {
+        return gestureDetector.onTouchEvent(event);
+    }
+
+    public interface OnChapterBoundariesOutListener {
+        public void onFirstPageOut();
+
+        public void onLastPageOut();
+    }
+
+    public interface OnChapterSingleTapListener {
+        public void onSingleTap();
+    }
+
+    public void setOnChapterBoundariesOutListener(OnChapterBoundariesOutListener onChapterBoundariesOutListener) {
+        mOnChapterBoundariesOutListener = onChapterBoundariesOutListener;
+    }
+
+    public void setOnChapterSingleTapListener(OnChapterSingleTapListener onChapterSingleTapListener) {
+        mOnChapterSingleTapListener = onChapterSingleTapListener;
+    }
+
+
+    private class ReaderViewGestureListener extends GestureDetector.SimpleOnGestureListener {
+
+        @Override
+        public boolean onSingleTapConfirmed(MotionEvent e) {
+            final int position = getCurrentItem();
+            final float positionX = e.getX();
+
+            if (positionX < getWidth() * LEFT_REGION) {
+                if (position != 0) {
+                    setCurrentItem(position - 1, true);
+                } else {
+                    if (mOnChapterBoundariesOutListener != null) {
+                        mOnChapterBoundariesOutListener.onFirstPageOut();
+                    }
+                }
+            } else if (positionX > getWidth() * RIGHT_REGION) {
+                if (position != getAdapter().getCount() - 1) {
+                    setCurrentItem(position + 1, true);
+                } else {
+                    if (mOnChapterBoundariesOutListener != null) {
+                        mOnChapterBoundariesOutListener.onLastPageOut();
+                    }
+                }
+            }
+
+            return true;
+        }
+
+    }
+
+}