CameraDemoActivity.java

/*
 * Copyright (C) 2012 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.mapdemo;

import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.CancelableCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.CompoundButton;
import android.widget.SeekBar;
import android.widget.Toast;

/**
 * This shows how to change the camera position for the map.
 */
public class CameraDemoActivity extends FragmentActivity {

    /**
     * The amount by which to scroll the camera. Note that this amount is in raw pixels, not dp
     * (density-independent pixels).
     */
    private static final int SCROLL_BY_PX = 100;

    static final CameraPosition BONDI =
            new CameraPosition.Builder().target(new LatLng(-33.891614, 151.276417))
                    .zoom(15.5f)
                    .bearing(300)
                    .tilt(50)
                    .build();

    static final CameraPosition SYDNEY =
            new CameraPosition.Builder().target(new LatLng(-33.87365, 151.20689))
                    .zoom(15.5f)
                    .bearing(0)
                    .tilt(25)
                    .build();

    private GoogleMap mMap;

    private CompoundButton mAnimateToggle;
    private CompoundButton mCustomDurationToggle;
    private SeekBar mCustomDurationBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.camera_demo);

        mAnimateToggle = (CompoundButton) findViewById(R.id.animate);
        mCustomDurationToggle = (CompoundButton) findViewById(R.id.duration_toggle);
        mCustomDurationBar = (SeekBar) findViewById(R.id.duration_bar);

        updateEnabledState();

        setUpMapIfNeeded();
    }

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {
        if (mMap == null) {
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
        }
    }

    /**
     * When the map is not ready the CameraUpdateFactory cannot be used. This should be called on
     * all entry points that call methods on the Google Maps API.
     */
    private boolean checkReady() {
        if (mMap == null) {
            Toast.makeText(this, R.string.map_not_ready, Toast.LENGTH_SHORT).show();
            return false;
        }
        return true;
    }

    /**
     * Called when the Go To Bondi button is clicked.
     */
    public void onGoToBondi(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.newCameraPosition(BONDI));
    }

    /**
     * Called when the Animate To Sydney button is clicked.
     */
    public void onGoToSydney(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.newCameraPosition(SYDNEY), new CancelableCallback() {
            @Override
            public void onFinish() {
                Toast.makeText(getBaseContext(), "Animation to Sydney complete", Toast.LENGTH_SHORT)
                        .show();
            }

            @Override
            public void onCancel() {
                Toast.makeText(getBaseContext(), "Animation to Sydney canceled", Toast.LENGTH_SHORT)
                        .show();
            }
        });
    }

    /**
     * Called when the stop button is clicked.
     */
    public void onStopAnimation(View view) {
        if (!checkReady()) {
            return;
        }

        mMap.stopAnimation();
    }

    /**
     * Called when the zoom in button (the one with the +) is clicked.
     */
    public void onZoomIn(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.zoomIn());
    }

    /**
     * Called when the zoom out button (the one with the -) is clicked.
     */
    public void onZoomOut(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.zoomOut());
    }

    /**
     * Called when the left arrow button is clicked. This causes the camera to move to the left
     */
    public void onScrollLeft(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.scrollBy(-SCROLL_BY_PX, 0));
    }

    /**
     * Called when the right arrow button is clicked. This causes the camera to move to the right.
     */
    public void onScrollRight(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.scrollBy(SCROLL_BY_PX, 0));
    }

    /**
     * Called when the up arrow button is clicked. The causes the camera to move up.
     */
    public void onScrollUp(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.scrollBy(0, -SCROLL_BY_PX));
    }

    /**
     * Called when the down arrow button is clicked. This causes the camera to move down.
     */
    public void onScrollDown(View view) {
        if (!checkReady()) {
            return;
        }

        changeCamera(CameraUpdateFactory.scrollBy(0, SCROLL_BY_PX));
    }

    /**
     * Called when the animate button is toggled
     */
    public void onToggleAnimate(View view) {
        updateEnabledState();
    }

    /**
     * Called when the custom duration checkbox is toggled
     */
    public void onToggleCustomDuration(View view) {
        updateEnabledState();
    }

    /**
     * Update the enabled state of the custom duration controls.
     */
    private void updateEnabledState() {
        mCustomDurationToggle.setEnabled(mAnimateToggle.isChecked());
        mCustomDurationBar
            .setEnabled(mAnimateToggle.isChecked() && mCustomDurationToggle.isChecked());
    }

    private void changeCamera(CameraUpdate update) {
        changeCamera(update, null);
    }

    /**
     * Change the camera position by moving or animating the camera depending on the state of the
     * animate toggle button.
     */
    private void changeCamera(CameraUpdate update, CancelableCallback callback) {
        if (mAnimateToggle.isChecked()) {
            if (mCustomDurationToggle.isChecked()) {
                int duration = mCustomDurationBar.getProgress();
                // The duration must be strictly positive so we make it at least 1.
                mMap.animateCamera(update, Math.max(duration, 1), callback);
            } else {
                mMap.animateCamera(update, callback);
            }
        } else {
            mMap.moveCamera(update);
        }
    }
}