Mega Code Archive
Draggable dot
<![CDATA[
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.apis.view;
import com.example.android.apis.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.DragEvent;
import android.view.View;
import android.widget.TextView;
import android.content.ClipData;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.*;
import android.os.SystemClock;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.DragEvent;
import android.view.View;
import android.widget.TextView;
class DraggableDot extends View {
static final String TAG = "DraggableDot";
private boolean mDragInProgress;
private boolean mHovering;
private boolean mAcceptsDrag;
TextView mReportView;
private Paint mPaint;
private TextPaint mLegendPaint;
private Paint mGlow;
private static final int NUM_GLOW_STEPS = 10;
private static final int GREEN_STEP = 0x0000FF00 / NUM_GLOW_STEPS;
private static final int WHITE_STEP = 0x00FFFFFF / NUM_GLOW_STEPS;
private static final int ALPHA_STEP = 0xFF000000 / NUM_GLOW_STEPS;
int mRadius;
int mAnrType;
CharSequence mLegend;
static final int ANR_NONE = 0;
static final int ANR_SHADOW = 1;
static final int ANR_DROP = 2;
void sleepSixSeconds() {
// hang forever; good for producing ANRs
long start = SystemClock.uptimeMillis();
do {
try { Thread.sleep(1000); } catch (InterruptedException e) {}
} while (SystemClock.uptimeMillis() < start + 6000);
}
// Shadow builder that can ANR if desired
class ANRShadowBuilder extends DragShadowBuilder {
boolean mDoAnr;
public ANRShadowBuilder(View view, boolean doAnr) {
super(view);
mDoAnr = doAnr;
}
@Override
public void onDrawShadow(Canvas canvas) {
if (mDoAnr) {
sleepSixSeconds();
}
super.onDrawShadow(canvas);
}
}
public DraggableDot(Context context, AttributeSet attrs) {
super(context, attrs);
setFocusable(true);
setClickable(true);
mLegend = "";
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setStrokeWidth(6);
mPaint.setColor(0xFFD00000);
mLegendPaint = new TextPaint();
mLegendPaint.setAntiAlias(true);
mLegendPaint.setTextAlign(Paint.Align.CENTER);
mLegendPaint.setColor(0xFFF0F0FF);
mGlow = new Paint();
mGlow.setAntiAlias(true);
mGlow.setStrokeWidth(1);
mGlow.setStyle(Paint.Style.STROKE);
// look up any layout-defined attributes
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.DraggableDot);
final int N = a.getIndexCount();
for (int i = 0; i < N; i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.DraggableDot_radius: {
mRadius = a.getDimensionPixelSize(attr, 0);
} break;
case R.styleable.DraggableDot_legend: {
mLegend = a.getText(attr);
} break;
case R.styleable.DraggableDot_anr: {
mAnrType = a.getInt(attr, 0);
} break;
}
}
Log.i(TAG, "DraggableDot @ " + this + " : radius=" + mRadius + " legend='" + mLegend
+ "' anr=" + mAnrType);
setOnLongClickListener(new View.OnLongClickListener() {
public boolean onLongClick(View v) {
ClipData data = ClipData.newPlainText("dot", "Dot : " + v.toString());
v.startDrag(data, new ANRShadowBuilder(v, mAnrType == ANR_SHADOW),
(Object)v, 0);
return true;
}
});
}
void setReportView(TextView view) {
mReportView = view;
}
@Override
protected void onDraw(Canvas canvas) {
float wf = getWidth();
float hf = getHeight();
final float cx = wf/2;
final float cy = hf/2;
wf -= getPaddingLeft() + getPaddingRight();
hf -= getPaddingTop() + getPaddingBottom();
float rad = (wf < hf) ? wf/2 : hf/2;
canvas.drawCircle(cx, cy, rad, mPaint);
if (mLegend != null && mLegend.length() > 0) {
canvas.drawText(mLegend, 0, mLegend.length(),
cx, cy + mLegendPaint.getFontSpacing()/2,
mLegendPaint);
}
// if we're in the middle of a drag, light up as a potential target
if (mDragInProgress && mAcceptsDrag) {
for (int i = NUM_GLOW_STEPS; i > 0; i--) {
int color = (mHovering) ? WHITE_STEP : GREEN_STEP;
color = i*(color | ALPHA_STEP);
mGlow.setColor(color);
canvas.drawCircle(cx, cy, rad, mGlow);
rad -= 0.5f;
canvas.drawCircle(cx, cy, rad, mGlow);
rad -= 0.5f;
}
}
}
@Override
protected void onMeasure(int widthSpec, int heightSpec) {
int totalDiameter = 2*mRadius + getPaddingLeft() + getPaddingRight();
setMeasuredDimension(totalDiameter, totalDiameter);
}
/**
* Drag and drop
*/
@Override
public boolean onDragEvent(DragEvent event) {
boolean result = false;
switch (event.getAction()) {
case DragEvent.ACTION_DRAG_STARTED: {
// claim to accept any dragged content
Log.i(TAG, "Drag started, event=" + event);
// cache whether we accept the drag to return for LOCATION events
mDragInProgress = true;
mAcceptsDrag = result = true;
// Redraw in the new visual state if we are a potential drop target
if (mAcceptsDrag) {
invalidate();
}
} break;
case DragEvent.ACTION_DRAG_ENDED: {
Log.i(TAG, "Drag ended.");
if (mAcceptsDrag) {
invalidate();
}
mDragInProgress = false;
mHovering = false;
} break;
case DragEvent.ACTION_DRAG_LOCATION: {
// we returned true to DRAG_STARTED, so return true here
Log.i(TAG, "... seeing drag locations ...");
result = mAcceptsDrag;
} break;
case DragEvent.ACTION_DROP: {
Log.i(TAG, "Got a drop! dot=" + this + " event=" + event);
if (mAnrType == ANR_DROP) {
sleepSixSeconds();
}
processDrop(event);
result = true;
} break;
case DragEvent.ACTION_DRAG_ENTERED: {
Log.i(TAG, "Entered dot @ " + this);
mHovering = true;
invalidate();
} break;
case DragEvent.ACTION_DRAG_EXITED: {
Log.i(TAG, "Exited dot @ " + this);
mHovering = false;
invalidate();
} break;
default:
Log.i(TAG, "other drag event: " + event);
result = mAcceptsDrag;
break;
}
return result;
}
private void processDrop(DragEvent event) {
final ClipData data = event.getClipData();
final int N = data.getItemCount();
for (int i = 0; i < N; i++) {
ClipData.Item item = data.getItemAt(i);
Log.i(TAG, "Dropped item " + i + " : " + item);
if (mReportView != null) {
String text = item.coerceToText(getContext()).toString();
if (event.getLocalState() == (Object) this) {
text += " : Dropped on self!";
}
mReportView.setText(text);
}
}
}
}
public class Test extends Activity {
TextView mResultText;
DraggableDot mHiddenDot;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView text = (TextView) findViewById(R.id.drag_text);
DraggableDot dot = (DraggableDot) findViewById(R.id.drag_dot_1);
dot.setReportView(text);
dot = (DraggableDot) findViewById(R.id.drag_dot_2);
dot.setReportView(text);
dot = (DraggableDot) findViewById(R.id.drag_dot_3);
dot.setReportView(text);
mHiddenDot = (DraggableDot) findViewById(R.id.drag_dot_hidden);
mHiddenDot.setReportView(text);
mResultText = (TextView) findViewById(R.id.drag_result_text);
mResultText.setOnDragListener(new View.OnDragListener() {
public boolean onDrag(View v, DragEvent event) {
final int action = event.getAction();
switch (action) {
case DragEvent.ACTION_DRAG_STARTED: {
// Bring up a fourth draggable dot on the fly. Note that it
// is properly notified about the ongoing drag, and lights up
// to indicate that it can handle the current content.
mHiddenDot.setVisibility(View.VISIBLE);
} break;
case DragEvent.ACTION_DRAG_ENDED: {
// Hide the surprise again
mHiddenDot.setVisibility(View.INVISIBLE);
// Report the drop/no-drop result to the user
final boolean dropped = event.getResult();
mResultText.setText(dropped ? "Dropped!" : "No drop");
} break;
}
return false;
}
});
}
}
//main.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2010 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Layout description of the DragAndDrop sample's main activity -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:dot="http://schemas.android.com/apk/res/com.example.android.apis"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TextView android:id="@+id/drag_explanation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="drag_explanation"
/>
<app.test.DraggableDot
android:id="@+id/drag_dot_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
dot:radius="64dp"
android:padding="15dp"
android:layout_below="@id/drag_explanation"
/>
<app.test.DraggableDot
android:id="@+id/drag_dot_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
dot:radius="64dp"
android:padding="15dp"
android:layout_below="@id/drag_explanation"
android:layout_toRightOf="@id/drag_dot_1"
dot:legend="Drag ANR"
dot:anr="thumbnail"
/>
<app.test.DraggableDot
android:id="@+id/drag_dot_3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
dot:radius="64dp"
android:padding="15dp"
android:layout_below="@id/drag_dot_1"
android:layout_alignLeft="@id/drag_dot_1"
dot:legend="Drop ANR"
dot:anr="drop"
/>
<app.test.DraggableDot
android:id="@+id/drag_dot_hidden"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
dot:radius="64dp"
android:padding="15dp"
android:layout_toRightOf="@id/drag_dot_3"
android:layout_alignTop="@id/drag_dot_3"
android:visibility="invisible"
dot:legend="Surprise!"
/>
<TextView android:id="@+id/drag_result_text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/drag_explanation"
android:layout_alignRight="@id/drag_explanation"
android:layout_toRightOf="@id/drag_dot_2"
/>
<TextView android:id="@+id/drag_text"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:layout_below="@id/drag_dot_3"
android:layout_alignLeft="@id/drag_dot_3"
/>
</RelativeLayout>
]]>