LazyIconView

LazyIconView.java

package jp.tondol.sample;

import java.net.HttpURLConnection;
import java.net.URL;

import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.StateListDrawable;
import android.os.AsyncTask;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;

public class LazyIconView extends ViewGroup {

	protected ImageView backgroundImageView;
	protected ImageView foregroundImageView;
	protected View clickableView;
	protected ProgressBarView progressBarView;

	protected int iconSize = 80;
	protected int thumbSize = 80;
	protected int marginSize = 2;

	protected final int DEFAULT_PROGRESS_BAR_SIZE = 40;

	public LazyIconView(Context context) {
		super(context);
		initComponents();
	}

	public LazyIconView(Context context, AttributeSet attrs) {
		super(context, attrs);
		initComponents();
	}

	public void initComponents() {
		removeAllViews();

		backgroundImageView = new ImageView(getContext());
		addView(backgroundImageView);

		foregroundImageView = new ImageView(getContext());
		addView(foregroundImageView);

		progressBarView = new ProgressBarView(getContext());
		progressBarView.setProgressBarSize(DEFAULT_PROGRESS_BAR_SIZE);
		progressBarView.setBackgroundColor(Color.BLACK);
		addView(progressBarView, new ViewGroup.LayoutParams(iconSize, iconSize));

		clickableView = new View(getContext());
		clickableView.setBackgroundDrawable(getStateList());
		addView(clickableView);

		updateLayout();
	}

	protected StateListDrawable getStateList() {
		StateListDrawable stateList = new StateListDrawable();
		stateList.addState(new int[] { android.R.attr.state_pressed },
				new ColorDrawable(Color.GREEN));
		stateList.addState(new int[] {},
				new ColorDrawable(Color.TRANSPARENT));
		return stateList;
	}

	public void updateLayout() {
		double measuredScale = getMeasuredScale();
		int m = (int) (marginSize * measuredScale);
		int s = (int) (thumbSize * measuredScale);
		backgroundImageView.layout(m, m, m + s, m + s);
		foregroundImageView.layout(0, 0, s, s);
		progressBarView.layout(0, 0, s, s);
		clickableView.layout(0, 0, s, s);
	}

	@Override
	protected void onLayout(boolean changed, int left, int top, int right,
			int bottom) {
		updateLayout();
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// 自身のdimentionを決定する
		setMeasuredDimension(getMeasuredSize(widthMeasureSpec),
				getMeasuredSize(heightMeasureSpec));

		// 子ビューのdimentionを決定する
		int size = (int) (thumbSize * getMeasuredScale());
		int spec = MeasureSpec.makeMeasureSpec(
				size, MeasureSpec.EXACTLY);
		backgroundImageView.measure(spec, spec);
		foregroundImageView.measure(spec, spec);
		progressBarView.measure(spec, spec);
		clickableView.measure(spec, spec);
	}

	protected int getMeasuredSize(int measureSpec) {
		int mode = MeasureSpec.getMode(measureSpec);
		int size = MeasureSpec.getSize(measureSpec);

		if (mode == MeasureSpec.EXACTLY) {
			return size;
		} else if (mode == MeasureSpec.AT_MOST) {
			return Math.min(size, iconSize);
		} else {
			return iconSize;
		}
	}

	protected double getMeasuredScale() {
		return (double) iconSize / (double) (thumbSize + marginSize);
	}

	public void setIconSize(int size) {
		iconSize = size;
	}

	public void setMarginSize(int size) {
		marginSize = size;
	}

	public void setThumbSize(int size) {
		thumbSize = size;
	}

	public void setProgressSize(int size) {
		progressBarView.setProgressBarSize(size);
	}

	public ImageView getForegroundImageView() {
		return foregroundImageView;
	}

	public ImageView getBackgroundImageView() {
		return backgroundImageView;
	}

	public View getClickableImageView() {
		return clickableView;
	}

	public void setForegroundImageUrl(String urlString) {
		(new LoadAsyncTask(urlString)).execute();
	}

	// 画像を取得する非同期タスククラス
	class LoadAsyncTask extends AsyncTask<Void, Void, Drawable> {
		private String urlString;

		public LoadAsyncTask(String urlString) {
			this.urlString = urlString;
		}

		@Override
		protected void onPreExecute() {
			super.onPreExecute();

			progressBarView.setVisibility(View.VISIBLE);
		}

		@Override
		protected void onPostExecute(Drawable result) {
			super.onPostExecute(result);

			if (result != null) {
				foregroundImageView.setImageDrawable(result);
				progressBarView.setVisibility(View.INVISIBLE);
			}
		}

		@Override
		protected Drawable doInBackground(Void... params) {
			try {
				URL resourceUrl = new URL(urlString);
				HttpURLConnection conn =
						(HttpURLConnection) resourceUrl.openConnection();
				conn.setRequestMethod("GET");
				return Drawable.createFromStream(conn.getInputStream(), null);
			} catch (Exception e) {
				android.util.Log.e("LazyIconView", e.toString());
				return null;
			}
		}
	}

	static class ProgressBarView extends RelativeLayout {

		protected ProgressBar progressBar;
		protected int progressBarSize = 40;

		public ProgressBarView(Context context) {
			super(context);
			initComponents();
		}

		public ProgressBarView(Context context, AttributeSet attrs) {
			super(context, attrs);
			initComponents();
		}

		public void initComponents() {
			removeAllViews();

			RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
					progressBarSize, progressBarSize);
			lp.addRule(RelativeLayout.CENTER_IN_PARENT);

			progressBar = new ProgressBar(getContext(), null,
					android.R.attr.progressBarStyle);
			progressBar.setLayoutParams(lp);

			addView(progressBar);
		}

		public int getProgressBarSize() {
			return progressBarSize;
		}

		public void setProgressBarSize(int size) {
			progressBarSize = size;
			initComponents();
		}
	}
}

SampleActivity.java

package jp.tondol.sample;

import android.app.Activity;
import android.app.AlertDialog;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.LinearLayout;

public class SampleActivity extends Activity {

	LazyIconView iconView;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		iconView = new LazyIconView(this);
		Drawable d = getResources().getDrawable(R.drawable.icon_background);

		iconView.setMarginSize(3); // 背景画像の影の幅
		iconView.setThumbSize(120); // 背景画像の一辺の長さ
		iconView.setIconSize(180); // 画面上に表示するときの大きさ
		iconView.getBackgroundImageView().setImageDrawable(d); // 背景画像を設定

		// アイコンに対してクリックリスナーを登録するときはこんな感じで
		iconView.getClickableImageView().setClickable(true);
		iconView.getClickableImageView().setOnClickListener(new OnClickListener(){
			@Override
			public void onClick(View v) {
				AlertDialog.Builder builder = new AlertDialog.Builder(SampleActivity.this);
				builder.setTitle("sample");
				builder.setMessage("onClick");
				builder.show();
			}
		});

		int FP = ViewGroup.LayoutParams.FILL_PARENT;
		LinearLayout layout = new LinearLayout(this);
		layout.setLayoutParams(new ViewGroup.LayoutParams(FP, FP));
		layout.setBackgroundColor(Color.WHITE);
		layout.addView(iconView);

		setContentView(layout);
	}

	// レイアウトのサイズが確定したタイミングで呼ばれる
	@Override
	public void onWindowFocusChanged(boolean hasFocus) {
		super.onWindowFocusChanged(hasFocus);

		if (hasFocus) {
			iconView.setForegroundImageUrl("http://tondol.com/static/image/icon.png"); // 読み込む画像を設定
		}
	}
}