画像のスクロールとズームを可能にするこのコードがありますが、画像が小さい場合でも、コードは画像を引き伸ばして画面全体を埋めます。画面全体を占有せずにコードを変更することで、画像を含むダイアログを表示し、ズームとスクロールを有効にしたいと考えています。
編集:以下のコードを使用して、スクロールを制限したり、画像のサイズを制限したりすることは可能ですか? 最初のディスプレイ（中央）にはデフォルトの画像サイズがあり、これは最小ズームアウトでもあります。画像がスクロール可能な最大サイズ (実際の画像サイズ) に達すると、デフォルトのサイズに戻ります。可能であれば、画像をスクロールできる領域も制御して、ズームインで迷子にならないようにします。
public class ZoomHelloActivity extends Activity {
// Physical display width and height.
private static int displayWidth = 0;
private static int displayHeight = 0;
static String img="";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Display display = ((WindowManager)
getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
displayWidth = display.getWidth();
displayHeight = display.getHeight();
//get intent
Bundle extras = getIntent().getExtras();
if (extras != null) {
Toast.makeText(this.getBaseContext(),"Inside: "+img.toString(),
Toast.LENGTH_SHORT).show();
img = extras.getString("img");
// and get whatever type user account id is
}
else{ Toast.makeText(this.getBaseContext(),"ERROR ni",
Toast.LENGTH_SHORT).show();}
setContentView(new SampleView(this));
}
private static class SampleView extends View {
private static Bitmap bmLargeImage; //bitmap large enough to be scrolled
private static Rect displayRect = null; //rect we display to
private Rect scrollRect = null; //rect we scroll over our bitmap with
private int scrollRectX = 0; //current left location of scroll rect
private int scrollRectY = 0; //current top location of scroll rect
private float scrollByX = 0; //x amount to scroll by
private float scrollByY = 0; //y amount to scroll by
private float startX = 0; //track x from one ACTION_MOVE to the next
private float startY = 0; //track y from one ACTION_MOVE to the next
public SampleView(Context context) {
super(context);
// Destination rect for our main canvas draw. It never changes.
displayRect = new Rect(0, 0, displayWidth, displayHeight);
// Scroll rect: this will be used to 'scroll around' over the
// bitmap in memory. Initialize as above.
scrollRect = new Rect(0, 0, displayWidth, displayHeight);
// Load a large bitmap into an offscreen area of memory.
int assignImg;
assignImg = Integer.parseInt(img);
bmLargeImage = BitmapFactory.decodeResource(getResources(),
assignImg);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// Remember our initial down event location.
startX = event.getRawX();
startY = event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
float x = event.getRawX();
float y = event.getRawY();
// Calculate move update. This will happen many times
// during the course of a single movement gesture.
scrollByX = x - startX; //move update x increment
scrollByY = y - startY; //move update y increment
startX = x; //reset initial values to latest
startY = y;
invalidate(); //force a redraw
break;
}
return true; //done with this event so consume it
}
@Override
protected void onDraw(Canvas canvas) {
int newScrollRectX = scrollRectX - (int)scrollByX;
int newScrollRectY = scrollRectY - (int)scrollByY;
// Don't scroll off the left or right edges of the bitmap.
if (newScrollRectX < 0)
newScrollRectX = 0;
else if (newScrollRectX > (bmLargeImage.getWidth() - displayWidth))
newScrollRectX = (bmLargeImage.getWidth() - displayWidth);
// Don't scroll off the top or bottom edges of the bitmap.
if (newScrollRectY < 0)
newScrollRectY = 0;
else if (newScrollRectY > (bmLargeImage.getHeight() - displayHeight))
newScrollRectY = (bmLargeImage.getHeight() - displayHeight);
// We have our updated scroll rect coordinates, set them and draw.
scrollRect.set(newScrollRectX, newScrollRectY,
newScrollRectX + displayWidth, newScrollRectY + displayHeight);
Paint paint = new Paint();
canvas.drawBitmap(bmLargeImage, scrollRect, displayRect, paint);
// Reset current scroll coordinates to reflect the latest updates,
// so we can repeat this update process.
scrollRectX = newScrollRectX;
scrollRectY = newScrollRectY;
}
}
}
編集：希望の出力：
