STEP - 1 : values --> attr.xml
<?xml version="1.0" encoding="utf-8"?><resources> <declare-styleable name="RearrangeableLayout"> <attr name="outlineWidth" format="dimension" /> <attr name="outlineColor" format="color" /> <attr name="selectionAlpha" format="float" /> <attr name="selectionZoom" format="float" /> </declare-styleable></resources>
STEP - 2 : activity_main.xml
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" > <propfinsolutions.realstate.app.com.testfifth.RearrangeableLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/rearrangeable_layout" android:layout_width="match_parent" android:layout_height="match_parent" android:clipToPadding="false" app:outlineWidth="2dp" app:outlineColor="#00FFFF" app:selectionAlpha="0.5" app:selectionZoom="1.2"> <!-- add child views with `android:id` attr to save position during orientation change --> <TextView android:id="@+id/texview" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Sample Demo" android:textSize="30sp" android:background="@android:color/darker_gray" android:layout_margin="15dp" /> <TextView android:id="@+id/textview2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Sample Demo with very large text that will overflow in width" android:textSize="30sp" android:background="@android:color/holo_green_light"/> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Button" android:textSize="30sp" android:layout_margin="15dp"/> <TextView android:id="@+id/textview3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Sample" android:textSize="15sp" android:background="@android:color/holo_orange_light" android:layout_margin="15dp"/> </propfinsolutions.realstate.app.com.testfifth.RearrangeableLayout></RelativeLayout>
STEP - 3: MainActivity.java
import android.graphics.Rect;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.ViewTreeObserver; public class MainActivity extends AppCompatActivity { private static final String TAG = "MainActivity"; private RearrangeableLayout root; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // initialize the RearrangeableLayout object root = (RearrangeableLayout) findViewById(R.id.rearrangeable_layout); // callback method to call childPositionListener() method childPosiitonListener(); // callback method to call preDrawListener() method preDrawListener(); } /** * In this method, Added a ChildPositionListener to the root layout to receive * position of child view whenever any child view is dragged */ public void childPosiitonListener(){ root.setChildPositionListener(new RearrangeableLayout.ChildPositionListener() { @Override public void onChildMoved(View childView, Rect oldPosition, Rect newPosition) { Log.e(TAG, childView.toString()); Log.e(TAG, oldPosition.toString() + " -> " + newPosition.toString()); } }); } /** * In this method, Added a PreviewListener to the root layout to receive update during * child view is dragging */ public void preDrawListener(){ root.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() { @Override public boolean onPreDraw() { Log.e(TAG, "onPrepreview"); Log.e(TAG, root.toString()); return true; } }); } }
STEP - 4 : RearrangeableLayout.java
import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.ColorMatrix;import android.graphics.ColorMatrixColorFilter;import android.graphics.Paint;import android.graphics.PointF;import android.graphics.Rect;import android.os.Parcelable;import android.util.AttributeSet;import android.util.Log;import android.util.SparseArray;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.view.animation.AccelerateInterpolator;import android.view.animation.Animation;import android.view.animation.LayoutAnimationController;import android.view.animation.TranslateAnimation;import android.widget.Toast; /** * Created by raja on 6/19/15. */public class RearrangeableLayout extends ViewGroup { private static final String TAG = "RearrangeableLayout"; private PointF mStartTouch; private View mSelectedChild; private float mSelectionZoom; private Paint mSelectionPaint; private Paint mOutlinePaint; private SparseArray<Parcelable> mContainer; /* callback to update clients whenever child is dragged */ private ChildPositionListener mListener; /* used by ChildPositionListener callback */ private Rect mChildStartRect; private Rect mChildEndRect; public RearrangeableLayout(Context context) { this(context, null); } public RearrangeableLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public RearrangeableLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(context, attrs); } private void init(Context context, AttributeSet attrs) { mStartTouch = null; mSelectedChild = null; mContainer = new SparseArray<Parcelable>(5); mListener = null; mChildStartRect = null; mChildEndRect = null; TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RearrangeableLayout); float strokeWidth = a.getDimension(R.styleable.RearrangeableLayout_outlineWidth, 2.0f); int color = a.getColor(R.styleable.RearrangeableLayout_outlineColor, Color.GRAY); float alpha = a.getFloat(R.styleable.RearrangeableLayout_selectionAlpha, 0.5f); mSelectionZoom = a.getFloat(R.styleable.RearrangeableLayout_selectionZoom, 1.2f); a.recycle(); float filter[] = new float[] { 1f, 0f, 0f, 0f, 0f, 0f, 1f, 0f, 0f, 0f, 0f, 0f, 1f, 0f, 0f, 0f, 0f, 0f, alpha, 0f }; ColorMatrixColorFilter colorFilter = new ColorMatrixColorFilter(new ColorMatrix(filter)); mOutlinePaint = new Paint(Paint.ANTI_ALIAS_FLAG); mOutlinePaint.setStyle(Paint.Style.STROKE); mOutlinePaint.setStrokeWidth(strokeWidth); mOutlinePaint.setColor(color); mOutlinePaint.setColorFilter(colorFilter); mSelectionPaint = new Paint(); mSelectionPaint.setColorFilter(colorFilter); Animation trans = new TranslateAnimation(Animation.ABSOLUTE, 0, Animation.ABSOLUTE, 0, Animation.RELATIVE_TO_PARENT, 1, Animation.RELATIVE_TO_PARENT, 0); trans.setDuration(500); trans.setInterpolator(new AccelerateInterpolator(1.0f)); LayoutAnimationController c = new LayoutAnimationController(trans, 0.25f); setLayoutAnimation(c); } @Override protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { return super.checkLayoutParams(p) && p instanceof LayoutParams; } @Override public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) { return new LayoutParams(getContext(), attrs); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int width = MeasureSpec.getSize(widthMeasureSpec); int height = MeasureSpec.getSize(heightMeasureSpec); width = Math.max(width, getMinimumWidth()); height = Math.max(height, getMinimumHeight()); //Log.d(TAG, String.format("onMeasure: (%d, %d)", width, height)); //measureChildren(widthMeasureSpec, heightMeasureSpec); for(int i=0; i<getChildCount(); i++) { View view = getChildAt(i); LayoutParams mp = (LayoutParams) view.getLayoutParams(); view.measure(MeasureSpec.makeMeasureSpec(width -mp.leftMargin -mp.rightMargin, MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(height -mp.topMargin -mp.bottomMargin, MeasureSpec.AT_MOST)); //int w = view.getMeasuredWidth(); //int h = view.getMeasuredHeight(); //Log.d(TAG, String.format("View #%d: (%d, %d)", i, w, h)); } setMeasuredDimension(width, height); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { if (mSelectedChild == null) { doInitialLayout(l, t, r, b, getChildCount()); } } private void doInitialLayout(int l, int t, int r, int b, int count) { int currentLeft = l; int currentTop = t; int prevChildBottom = -1; for (int i=0; i<count; i++) { View view = getChildAt(i); LayoutParams mp = (LayoutParams) view.getLayoutParams(); int width = view.getMeasuredWidth(); int height = view.getMeasuredHeight(); int left, top, right, bottom; if (view.getVisibility() != View.GONE && !mp.moved) { if (currentTop+height > b || l+width > r) { Toast.makeText(getContext(), "Couldn't fit a child View, skipping it", Toast.LENGTH_SHORT) .show(); Log.d(TAG, "Couldn't fit a child View, skipping it"); continue; } if (currentLeft+width > r) { left = l + mp.leftMargin; currentTop = prevChildBottom; } else { left = currentLeft + mp.topMargin; } top = currentTop + mp.topMargin; right = left + width; bottom = top + height; //Log.d(TAG, String.format("Layout #%d: (%d, %d, %d, %d)", i, left, top, right, bottom)); mp.left = left; mp.top = top; view.layout(left, top, right, bottom); currentLeft = right + mp.rightMargin; prevChildBottom = bottom + mp.bottomMargin; } else if (mp.moved && view != mSelectedChild) { int x1 = Math.round(mp.left); int y1 = Math.round(mp.top); int x2 = Math.round(mp.left) + width; int y2 = Math.round(mp.top) + height; view.layout(x1, y1, x2, y2); } } } /** * this method can be used to force layout on a child * to recalculate its hit-rect, * otherwise outline border of the selected child is * drawn at the old position */ private void layoutSelectedChild(LayoutParams lp) { int l = Math.round(lp.left); int t = Math.round(lp.top); int r = l + mSelectedChild.getMeasuredWidth(); int b = t + mSelectedChild.getMeasuredHeight(); lp.moved = true; mSelectedChild.layout(l, t, r, b); } @Override protected void dispatchDraw(Canvas canvas) { if (mSelectedChild != null) { mSelectedChild.setVisibility(View.INVISIBLE); } super.dispatchDraw(canvas); if (mSelectedChild != null) { Rect rect = new Rect(); mSelectedChild.getHitRect(rect); int restorePoint = canvas.save(); canvas.scale(mSelectionZoom, mSelectionZoom, rect.centerX(), rect.centerY()); canvas.drawRect(rect, mOutlinePaint); mSelectedChild.setDrawingCacheEnabled(true); Bitmap child = mSelectedChild.getDrawingCache(); if (child != null) { LayoutParams lp = (LayoutParams) mSelectedChild.getLayoutParams(); canvas.drawBitmap(child, lp.left, lp.top, mSelectionPaint); } else { Log.d(TAG, "drawingCache not found! Maybe because of hardware acceleration"); mSelectedChild.draw(canvas); } canvas.restoreToCount(restorePoint); } } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { float x = ev.getX(); float y= ev.getY(); if (ev.getActionMasked() == MotionEvent.ACTION_MOVE) { prepareTouch(x, y); return true; } return false; } @Override public boolean onTouchEvent(MotionEvent event) { float x = event.getX(); float y = event.getY(); //mViewDragHelper.processTouchEvent(event); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: prepareTouch(x, y); break; case MotionEvent.ACTION_MOVE: if (mSelectedChild != null && mStartTouch != null) { LayoutParams lp = (LayoutParams) mSelectedChild.getLayoutParams(); float dx = x - mStartTouch.x; float dy = y - mStartTouch.y; lp.left = lp.initial.x + dx; if (lp.left < 0.0f) { lp.left = 0.0f; } lp.top = lp.initial.y + dy; if (lp.top < 0.0f) { lp.top = 0.0f; } /* layout child otherwise hit-rect is not recalculated */ layoutSelectedChild(lp); invalidate(); } break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: default: if (mSelectedChild != null) { if (mListener != null && mChildStartRect != null) { mChildEndRect = new Rect(); mSelectedChild.getHitRect(mChildEndRect); mListener.onChildMoved(mSelectedChild, mChildStartRect, mChildEndRect); } mSelectedChild.setVisibility(View.VISIBLE); mSelectedChild = null; } break; } return true; } private void prepareTouch(float x, float y) { mStartTouch = null; mSelectedChild = findChildViewInsideTouch(Math.round(x), Math.round(y)); if (mSelectedChild != null) { bringChildToFront(mSelectedChild); LayoutParams lp = (LayoutParams) mSelectedChild.getLayoutParams(); lp.initial = new PointF(lp.left, lp.top); mStartTouch = new PointF(x, y); if (mChildStartRect == null) { mChildStartRect = new Rect(); mSelectedChild.getHitRect(mChildStartRect); } } } /** * Search by hightest index to lowest so that the * most recently touched child is found first * * @return selectedChild */ private View findChildViewInsideTouch(int x, int y) { for(int i=getChildCount()-1; i>=0; i--) { View view = getChildAt(i); Rect rect = new Rect(); view.getHitRect(rect); if (rect.contains(x, y)) { mChildStartRect = rect; return view; } } return null; } public static class LayoutParams extends MarginLayoutParams { float left; float top; PointF initial; boolean moved; public LayoutParams(Context c, AttributeSet attrs) { super(c, attrs); left = -1.0f; top = -1.0f; initial = new PointF(0.0f, 0.0f); moved = false; } } @Override protected void onRestoreInstanceState(Parcelable state) { if (!(state instanceof SavedState)) { super.onRestoreInstanceState(state); return; } SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); mContainer = ss.container; for (int i=0; i<getChildCount(); i++) { View view = getChildAt(i); LayoutParams lp = (LayoutParams) view.getLayoutParams(); if (view.getId() != NO_ID) { SavedState s = (SavedState) mContainer.get(view.getId()); lp.left = s.left; lp.top = s.top; lp.moved = s.movedFlag; } } } @Override protected Parcelable onSaveInstanceState() { for (int i=0; i<getChildCount(); i++) { View view = getChildAt(i); LayoutParams lp = (LayoutParams) view.getLayoutParams(); view.saveHierarchyState(mContainer); if (view.getId() != NO_ID) { SavedState s = new SavedState(mContainer.get(view.getId())); s.left = lp.left; s.top = lp.top; s.movedFlag = lp.moved; mContainer.put(view.getId(), s); } } Parcelable p = super.onSaveInstanceState(); SavedState ss = new SavedState(p); ss.container = mContainer; return ss; } private static class SavedState extends BaseSavedState { float left, top; boolean movedFlag; SparseArray<Parcelable> container; public SavedState(Parcelable p) { super(p); } } /** * set ChildPositionListener to receive updates whenever child is moved * * @param listener */ public void setChildPositionListener(ChildPositionListener listener) { mListener = listener; } public interface ChildPositionListener { /** * this callback is invoked whenever child is moved * * @param childView the current child view that was dragged * @param oldPosition the original position from where child was dragged * @param newPosition the new position where child is currently laid */ void onChildMoved(View childView, Rect oldPosition, Rect newPosition); } @Override public String toString() { StringBuilder out = new StringBuilder(128); out.append(TAG); out.append(" mSelectedChild: "); if (mSelectedChild != null) { out.append(this.mSelectedChild.toString()); } return out.toString(); } }
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