Back to project page HappyBirthday.
The source code is released under:
Apache License
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package tk.eatheat.happybirthday; /*from w w w . j a v a2s. co m*/ import java.util.Collections; import java.util.ArrayList; import android.app.Activity; import android.content.Context; import android.graphics.Point; import android.os.Handler; import android.os.SystemClock; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.view.animation.AlphaAnimation; import android.view.animation.Animation; import android.view.animation.AnimationSet; import android.view.animation.ScaleAnimation; import android.view.animation.TranslateAnimation; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView.OnItemClickListener; import android.widget.ImageView; public class DraggableGridView extends ViewGroup implements View.OnTouchListener, View.OnClickListener, View.OnLongClickListener { //layout vars public static float childRatio = .9f; protected int colCount, childSize, padding, dpi, scroll = 0; protected float lastDelta = 0; protected Handler handler = new Handler(); //dragging vars protected int dragged = -1, lastX = -1, lastY = -1, lastTarget = -1; protected boolean enabled = true, touching = false; //anim vars public static int animT = 150; protected ArrayList<Integer> newPositions = new ArrayList<Integer>(); //listeners protected OnRearrangeListener onRearrangeListener; protected OnClickListener secondaryOnClickListener; private OnItemClickListener onItemClickListener; //CONSTRUCTOR AND HELPERS public DraggableGridView (Context context, AttributeSet attrs) { super(context, attrs); setListeners(); handler.removeCallbacks(updateTask); handler.postAtTime(updateTask, SystemClock.uptimeMillis() + 500); setChildrenDrawingOrderEnabled(true); DisplayMetrics metrics = new DisplayMetrics(); ((Activity)context).getWindowManager().getDefaultDisplay().getMetrics(metrics); dpi = metrics.densityDpi; } protected void setListeners() { setOnTouchListener(this); super.setOnClickListener(this); setOnLongClickListener(this); } @Override public void setOnClickListener(OnClickListener l) { secondaryOnClickListener = l; } protected Runnable updateTask = new Runnable() { public void run() { if (dragged != -1) { if (lastY < padding * 3 && scroll > 0) scroll -= 20; else if (lastY > getBottom() - getTop() - (padding * 3) && scroll < getMaxScroll()) scroll += 20; } else if (lastDelta != 0 && !touching) { scroll += lastDelta; lastDelta *= .9; if (Math.abs(lastDelta) < .25) lastDelta = 0; } clampScroll(); onLayout(true, getLeft(), getTop(), getRight(), getBottom()); handler.postDelayed(this, 25); } }; //OVERRIDES @Override public void addView(View child) { super.addView(child); newPositions.add(-1); }; @Override public void removeViewAt(int index) { super.removeViewAt(index); newPositions.remove(index); }; //LAYOUT @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { //compute width of view, in dp float w = (r - l) / (dpi / 160f); //determine number of columns, at least 2 colCount = 2; int sub = 240; w -= 280; while (w > 0) { colCount++; w -= sub; sub += 40; } //determine childSize and padding, in px childSize = (r - l) / colCount; childSize = Math.round(childSize * childRatio); padding = ((r - l) - (childSize * colCount)) / (colCount + 1); for (int i = 0; i < getChildCount(); i++) if (i != dragged) { Point xy = getCoorFromIndex(i); getChildAt(i).layout(xy.x, xy.y, xy.x + childSize, xy.y + childSize); } } @Override protected int getChildDrawingOrder(int childCount, int i) { if (dragged == -1) return i; else if (i == childCount - 1) return dragged; else if (i >= dragged) return i + 1; return i; } public int getIndexFromCoor(int x, int y) { int col = getColOrRowFromCoor(x), row = getColOrRowFromCoor(y + scroll); if (col == -1 || row == -1) //touch is between columns or rows return -1; int index = row * colCount + col; if (index >= getChildCount()) return -1; return index; } protected int getColOrRowFromCoor(int coor) { coor -= padding; for (int i = 0; coor > 0; i++) { if (coor < childSize) return i; coor -= (childSize + padding); } return -1; } protected int getTargetFromCoor(int x, int y) { if (getColOrRowFromCoor(y + scroll) == -1) //touch is between rows return -1; //if (getIndexFromCoor(x, y) != -1) //touch on top of another visual //return -1; int leftPos = getIndexFromCoor(x - (childSize / 4), y); int rightPos = getIndexFromCoor(x + (childSize / 4), y); if (leftPos == -1 && rightPos == -1) //touch is in the middle of nowhere return -1; if (leftPos == rightPos) //touch is in the middle of a visual return -1; int target = -1; if (rightPos > -1) target = rightPos; else if (leftPos > -1) target = leftPos + 1; if (dragged < target) return target - 1; //Toast.makeText(getContext(), "Target: " + target + ".", Toast.LENGTH_SHORT).show(); return target; } protected Point getCoorFromIndex(int index) { int col = index % colCount; int row = index / colCount; return new Point(padding + (childSize + padding) * col, padding + (childSize + padding) * row - scroll); } public int getIndexOf(View child) { for (int i = 0; i < getChildCount(); i++) if (getChildAt(i) == child) return i; return -1; } //EVENT HANDLERS public void onClick(View view) { if (enabled) { if (secondaryOnClickListener != null) secondaryOnClickListener.onClick(view); if (onItemClickListener != null && getLastIndex() != -1) onItemClickListener.onItemClick(null, getChildAt(getLastIndex()), getLastIndex(), getLastIndex() / colCount); } } public boolean onLongClick(View view) { if (!enabled) return false; int index = getLastIndex(); if (index != -1) { dragged = index; animateDragged(); return true; } return false; } public boolean onTouch(View view, MotionEvent event) { int action = event.getAction(); switch (action & MotionEvent.ACTION_MASK) { case MotionEvent.ACTION_DOWN: enabled = true; lastX = (int) event.getX(); lastY = (int) event.getY(); touching = true; break; case MotionEvent.ACTION_MOVE: int delta = lastY - (int)event.getY(); if (dragged != -1) { //change draw location of dragged visual int x = (int)event.getX(), y = (int)event.getY(); int l = x - (3 * childSize / 4), t = y - (3 * childSize / 4); getChildAt(dragged).layout(l, t, l + (childSize * 3 / 2), t + (childSize * 3 / 2)); //check for new target hover int target = getTargetFromCoor(x, y); if (lastTarget != target) { if (target != -1) { animateGap(target); lastTarget = target; } } } else { scroll += delta; clampScroll(); if (Math.abs(delta) > 2) enabled = false; onLayout(true, getLeft(), getTop(), getRight(), getBottom()); } lastX = (int) event.getX(); lastY = (int) event.getY(); lastDelta = delta; break; case MotionEvent.ACTION_UP: if (dragged != -1) { View v = getChildAt(dragged); if (lastTarget != -1) reorderChildren(); else { Point xy = getCoorFromIndex(dragged); v.layout(xy.x, xy.y, xy.x + childSize, xy.y + childSize); } v.clearAnimation(); if (v instanceof ImageView) ((ImageView)v).setAlpha(255); lastTarget = -1; dragged = -1; } touching = false; break; } if (dragged != -1) return true; return false; } //EVENT HELPERS protected void animateDragged() { View v = getChildAt(dragged); int x = getCoorFromIndex(dragged).x + childSize / 2, y = getCoorFromIndex(dragged).y + childSize / 2; int l = x - (3 * childSize / 4), t = y - (3 * childSize / 4); v.layout(l, t, l + (childSize * 3 / 2), t + (childSize * 3 / 2)); AnimationSet animSet = new AnimationSet(true); ScaleAnimation scale = new ScaleAnimation(.667f, 1, .667f, 1, childSize * 3 / 4, childSize * 3 / 4); scale.setDuration(animT); AlphaAnimation alpha = new AlphaAnimation(1, .5f); alpha.setDuration(animT); animSet.addAnimation(scale); animSet.addAnimation(alpha); animSet.setFillEnabled(true); animSet.setFillAfter(true); v.clearAnimation(); v.startAnimation(animSet); } protected void animateGap(int target) { for (int i = 0; i < getChildCount(); i++) { View v = getChildAt(i); if (i == dragged) continue; int newPos = i; if (dragged < target && i >= dragged + 1 && i <= target) newPos--; else if (target < dragged && i >= target && i < dragged) newPos++; //animate int oldPos = i; if (newPositions.get(i) != -1) oldPos = newPositions.get(i); if (oldPos == newPos) continue; Point oldXY = getCoorFromIndex(oldPos); Point newXY = getCoorFromIndex(newPos); Point oldOffset = new Point(oldXY.x - v.getLeft(), oldXY.y - v.getTop()); Point newOffset = new Point(newXY.x - v.getLeft(), newXY.y - v.getTop()); TranslateAnimation translate = new TranslateAnimation(Animation.ABSOLUTE, oldOffset.x, Animation.ABSOLUTE, newOffset.x, Animation.ABSOLUTE, oldOffset.y, Animation.ABSOLUTE, newOffset.y); translate.setDuration(animT); translate.setFillEnabled(true); translate.setFillAfter(true); v.clearAnimation(); v.startAnimation(translate); newPositions.set(i, newPos); } } protected void reorderChildren() { //FIGURE OUT HOW TO REORDER CHILDREN WITHOUT REMOVING THEM ALL AND RECONSTRUCTING THE LIST!!! if (onRearrangeListener != null) onRearrangeListener.onRearrange(dragged, lastTarget); ArrayList<View> children = new ArrayList<View>(); for (int i = 0; i < getChildCount(); i++) { getChildAt(i).clearAnimation(); children.add(getChildAt(i)); } removeAllViews(); while (dragged != lastTarget) if (lastTarget == children.size()) // dragged and dropped to the right of the last element { children.add(children.remove(dragged)); dragged = lastTarget; } else if (dragged < lastTarget) // shift to the right { Collections.swap(children, dragged, dragged + 1); dragged++; } else if (dragged > lastTarget) // shift to the left { Collections.swap(children, dragged, dragged - 1); dragged--; } for (int i = 0; i < children.size(); i++) { newPositions.set(i, -1); addView(children.get(i)); } onLayout(true, getLeft(), getTop(), getRight(), getBottom()); } public void scrollToTop() { scroll = 0; } public void scrollToBottom() { scroll = Integer.MAX_VALUE; clampScroll(); } protected void clampScroll() { int stretch = 3, overreach = getHeight() / 2; int max = getMaxScroll(); max = Math.max(max, 0); if (scroll < -overreach) { scroll = -overreach; lastDelta = 0; } else if (scroll > max + overreach) { scroll = max + overreach; lastDelta = 0; } else if (scroll < 0) { if (scroll >= -stretch) scroll = 0; else if (!touching) scroll -= scroll / stretch; } else if (scroll > max) { if (scroll <= max + stretch) scroll = max; else if (!touching) scroll += (max - scroll) / stretch; } } protected int getMaxScroll() { int rowCount = (int)Math.ceil((double)getChildCount()/colCount), max = rowCount * childSize + (rowCount + 1) * padding - getHeight(); return max; } public int getLastIndex() { return getIndexFromCoor(lastX, lastY); } //OTHER METHODS public void setOnRearrangeListener(OnRearrangeListener l) { this.onRearrangeListener = l; } public void setOnItemClickListener(OnItemClickListener l) { this.onItemClickListener = l; } }