I'm learning how to work with LayoutParams. there is something I don't understand about setting layout params. here is my code:
layout = findViewById(R.id.relative_layout);
img = findViewById(R.id.img_view);
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) img.getLayoutParams();
img.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
params.addRule(RelativeLayout.CENTER_IN_PARENT);
img.setLayoutParams(params); //Setting LayoutParams?
}
});
If I put this code directly in OnCreate() method, it works fine but why when I transfer it inside an OnClickListener, I need to set the layout params again? what logic is behind this?
You are modifying the Params after they are being set. This means that the current solution for solving the constraints optimally is not valid anymore, and they need to be recalculated. By changing this one constraint, your whole layout may change.
By setting the layout params on the layout again, it's resolving and recalculating new positions for every view, including your newly added constraint. As long as you don't call recalculation methods, the old layout will be used.
Related
This is my first time with android programming and I got stuck.
Now I'm trying to add view dynamically which contains toggle buttons, and edittext. However, whenever I select toggle button, options I created only works on last created view.
Options are simple. There are two toggle buttons and they can be clicked mutually exclusive
example
which means whenever I add new views such as B and C in above, the options are only worked on C while not in B. How can I make it to work on every view?
public void onAddField(View v){
LayoutInflater inflater=(LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View rowView=inflater.inflate(R.layout.data_gledger_add_new,null);
tbg_add=(ToggleButton)rowView.findViewById(R.id.add_toggle_gledger);
tbc_add=(ToggleButton)rowView.findViewById(R.id.add_toggle_credit);
if(create_box<4){
csl.addView(rowView,csl.getChildCount()-1);
Log.d("create_box",String.valueOf(create_box));
create_box++;
}
else{
Log.d("create_box","full");
create_box=4;
}
tbg_add.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
if(tbg_add.isChecked()){
get_add_cla="menu1";
tbg_add.setTextColor(getResources().getColor(R.color.color_white));
tbc_add.setChecked(false);
tbc_add.setTextColor(getResources().getColor(R.color.color_black));
}
else{
get_add_cla="";
tbg_add.setTextColor(getResources().getColor(R.color.color_black));
}
}
});
//대변 선택
tbc_add.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
if(tbc_add.isChecked()){
get_add_cla="menu2";
tbc_add.setTextColor(getResources().getColor(R.color.color_white));
tbg_add.setChecked(false);
tbg_add.setTextColor(getResources().getColor(R.color.color_black));
}
else{
get_add_cla="";
tbc_add.setTextColor(getResources().getColor(R.color.color_black));
}
}
});
}
I forgot to mention that views are added by clicking button.
android:onClick="onAddField"
The problem almost certainly stems from the fact that you are re-using instance fields (tbg_add and tbc_add) as add new views dynamically.
tbg_add=(ToggleButton)rowView.findViewById(R.id.add_toggle_gledger);
tbc_add=(ToggleButton)rowView.findViewById(R.id.add_toggle_credit);
Because you are re-assigning these fields and also referencing them from the click listeners, you'll always be referencing the most recently created toggle buttons.
Change these to be local variables and everything should work fine.
ToggleButton ledger=(ToggleButton)rowView.findViewById(R.id.add_toggle_gledger);
ToggleButton credit=(ToggleButton)rowView.findViewById(R.id.add_toggle_credit);
Unrelated to your problem, but also something you should fix, is the fact that you're passing null as the second parameter to your inflate() call:
final View rowView=inflater.inflate(R.layout.data_gledger_add_new,null);
When you pass null in this manner, the system won't have any ability to correctly handle the LayoutParams (anything starting with android:layout_ in the xml file) for the newly-inflated view.
You know that you're going to wind up adding the rowView to your csl view, so you should pass that as the second parameter. Once you do that, you also have to pass false as a third parameter to make sure that the inflate() call actually returns the rowView and not its new parent (csl).
final View rowView=inflater.inflate(R.layout.data_gledger_add_new, csl, false);
I have tried to draw a shape for a long time without an answer. I used setContentView(view) for that view. However, I have another setContentView:
setContentView(R.layout.activity_main);//Buttons, Views from XML...
setContentView( mCustomDrawableView);//Custom Shape
Problem is, it only shows ONE view, the shape. The Buttons defined on XML are gone. Basically whichever setContentView(view) is called last is the only View who is drawed. I've also tried many other ways to draw the shape without an answer that works.
I have seen that multiple setContentView do overlap each other, but this is the only way that partially works. Any way to display both Views or another way to draw a shape and my XML Views?
EDIT:
My shape is made in java, not XML
EDIT 2:
Here is my customShape Class:
public class CustomDrawableView extends View {
private ShapeDrawable mDrawable;
public CustomDrawableView(Context context) {
super(context);
int x = 10;
int y = 10;
mDrawable = new ShapeDrawable(new RectShape());
// If the color isn't set, the shape uses black as the default.
mDrawable.getPaint().setColor(0xff74AC23);
mDrawable.setBounds(x,y,x+10,y+10);
}
protected void onDraw(Canvas canvas) {
mDrawable.draw(canvas);
}
}
OK ... setContentView is something which takes a layout/view/whatever and the input defines the contents of the activity/fragment your are setting it to.
So of course your first call does the whole layout, and the second wipes that and sets the content to what you're sending to it.
The thing is to have your view and then add it to a layout. If you have any view in your initial setContentView xml named (+id) and defined (Layout x = getfromid(r.id.x) you can then add your view to that layout with x.addview(myview) or x.addview(CustomDrawableView(context)).
-edit for clarification-
An Activity/Fragment has a Layout which you set using setContentView. You do this once, normally. A Layout defines where Views are placed.
So, you setContentView(your.xml) in onCreate. If you have a programmatic View class, you can then do two things: add new YourView to a named and specified layout in your act/frag (using any layout defined in xml, passed to your frag/act in the xml passed in setContentView and then defined by Layout x = findViewById(R.id.idoflayoutinxmlinfield 'android:id="#+id/x") in code.
Then you can x.addview(new MyView(context)) or Myview z = new MyView(context) and x.addView(z);
-edit2-
When you get better, you can also just add your custom View to the original layout by adding it to the original xml definition.
-edit3-
Sigh. OK. Here it is:
In your activities java file:
RelativeLayout myRellayout;
#Override
public void onCreate(){
setContenView(your.xml)
myRelLayout = findViewByID(R.id.myrellayout);
myRelLayout.addView(new MyCustomView(this));
//or define your custom view and the add it by:
//MyCustomView mcv = new MyCustomView(this);
//myRelLayout.addView(mcv);
}
And your xml should contain any layout like this:
<RelativeLayout
android:id="#+id/myrellayout"
android:width="whatever"
android:height="whatever"
/>
I have written an app which has a screen view containing a thumbnail that I want to expand to full screen view (with pan and zoom) when I click it.
The large view with pan an zoom works fine, but I want to return to the original view when I click the large image.
final TouchImageView imgBig = new TouchImageView(Dashboard.this);
final ImageView img = (ImageView) findViewById(R.id.graph);
final Bitmap bitmap = result.getImage();
img.setImageBitmap(bitmap);
img.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
imgBig.setImageBitmap(bitmap);
imgBig.setMaxZoom(4f);
setContentView(imgBig);
imgBig.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// What do I need to do here to return to original thumbnail screen view?
}
});
}
});
Have tried a number of things without success!
Just the original setContentView(R.layout.main) will set it back.
It might be better to have an ImageView in the layout xml and set its image and show and hide it. Otherwise you are stuck with just one view which may be limiting.
When you do a setContentView its initializing your activity with that content. So if you want to just put something on top of it you could just have a hidden view. In your layout xml code make an image view that sits on top of all the other views. Then set its visibility="gone" so its hidden.
Then in your onClick instead of calling setContentView just set the image bitmap like you do and call imgBig.setVisibility(View.Gone or View.Visible) to show or hide your big image.
Another possibility is to have 2 activities. And call startActivity to show your big image and then finish to go back to the other activity like it was.
Another possibility is to use fragments, but that probably more involved.
I want to add a line above the action bar like in the "pocket"-app. How can i do this?
Here is a picture for example:
Thanks
tomtom
Taking advantage of an Activity's WindowManager, we can draw any view we want on top. Here's some (half-pseudo) code that should help:
// Create an instance of some View that does the actual drawing of the line
View customView = new CustomView(<some context>);
// Figure out the window we have to work with
Rect rect = new Rect();
getWindow().getDecorView().getWindowVisibleDisplayFrame(rect);
// Make sure the view is measured before doing this
int requestedHeight = customView.getLayoutParams().height;
// setup the params of the new view we'll attach
WindowManager.LayoutParams wlp = new WindowManager.LayoutParams(
rect.width(), requestedHeight,
WindowManager.LayoutParams.TYPE_APPLICATION_PANEL,
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE |
WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE |
WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN,
PixelFormat.TRANSLUCENT);
// set the parameters so we fit on the top left of the window
wlp.x = 0;
wlp.y = rect.top;
wlp.gravity = Gravity.TOP;
// finally add it to the screen
getWindowManager().addView(header, wlp);
The only thing to be careful is that you can't run that code from onCreate() or any lifecycle method of the Activity because the Window won't have been created yet (You'll get a BadTokenException). One way might be post a Runnable on the Window's DecorView so that your code to add the CustomView runs after the Window is created:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
getWindow().getDecorView().post(<Runnable that execs code above>);
}
As for the actual CustomView that will display that multi-coloured bar, I feel like that's a good exercise :-)
All you'd need to do is have the onDraw() method use canvas.drawRect() with specific x and widths.
Hope that helps.
What Pocket does
As for how Pocket actually does it. If you use HierarchyViewer on the Pocket app, you'll be able to determine that Pocket uses a custom class for their ActionBar. Since they already rebuild all the features of the ActionBar for their needs, in their case, adding the line is like adding a regular View to some ViewGroup.
I have an activity that has a TabHost containing a set of TabSpecs each with a listview containing the items to be displayed by the tab. When each TabSpec is created, I set an icon to be displayed in the tab header.
The TabSpecs are created in this way within a setupTabs() method which loops to create the appropriate number of tabs:
TabSpec ts = mTabs.newTabSpec("tab");
ts.setIndicator("TabTitle", iconResource);
ts.setContent(new TabHost.TabContentFactory(
{
public View createTabContent(String tag)
{
...
}
});
mTabs.addTab(ts);
There are a couple of instances where I want to be able to change the icon which is displayed in each tab during the execution of my program. Currently, I am deleting all the tabs, and calling the above code again to re-create them.
mTabs.getTabWidget().removeAllViews();
mTabs.clearAllTabs(true);
setupTabs();
Is there a way to replace the icon that is being displayed without deleting and re-creating all of the tabs?
The short answer is, you're not missing anything. The Android SDK doesn't provide a direct method to change the indicator of a TabHost after it's been created. The TabSpec is only used to build the tab, so changing the TabSpec after the fact will have no effect.
I think there's a workaround, though. Call mTabs.getTabWidget() to get a TabWidget object. This is just a subclass of ViewGroup, so you can call getChildCount() and getChildAt() to access individual tabs within the TabWidget. Each of these tabs is also a View, and in the case of a tab with a graphical indicator and a text label, it's almost certainly some other ViewGroup (maybe a LinearLayout, but it doesn't matter) that contains an ImageView and a TextView. So with a little fiddling with the debugger or Log.i, you should be able to figure out a recipe to get the ImageView and change it directly.
The downside is that if you're not careful, the exact layout of the controls within a tab could change and your app could break. Your initial solution is perhaps more robust, but then again it might lead to other unwanted side effects like flicker or focus problems.
Just to confirm dominics answer, here's his solution in code (that actually works):
tabHost.setOnTabChangedListener(new OnTabChangeListener() {
public void onTabChanged(String tabId) {
if (TAB_MAP.equals(tabId)) {
ImageView iv = (ImageView) tabHost.getTabWidget().getChildAt(0).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_map_black));
iv = (ImageView) tabHost.getTabWidget().getChildAt(1).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_list_white));
} else if (TAB_LIST.equals(tabId)) {
ImageView iv = (ImageView) tabHost.getTabWidget().getChildAt(0).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_map_white));
iv = (ImageView) tabHost.getTabWidget().getChildAt(1).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_list_black));
}
}
});
Of course it's not polished at all and using those direct indices in getChildAt() is not nice at all...
See my post with code example regarding Customized Android Tabs.
Thanks
Spct
This is what I did and it works for me. I created this function in the activity that extends from TabBarActivity
public void updateTab(int stringID) {
ViewGroup identifyView = (ViewGroup)getTabWidget().getChildAt(0);
TextView v = (TextView)identifyView.getChildAt(identifyView.getChildCount() - 1);
v.setText(stringID);
}
You can modify this function to change the image instead of text or you can change both, also you can modify this to get any tab child. I was particularly interested in modifying the text of the first tab at runtime.
I called this function from the relevant activity using this call
getParent().updateTab(R.string.tab_bar_analyze);
Try This:
tabHost.setOnTabChangedListener(new OnTabChangeListener() {
public void onTabChanged(String tabId) {
if (TAB_MAP.equals(tabId)) {
ImageView iv = (ImageView) tabHost.getTabWidget().getChildAt(0).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_map_black));
iv = (ImageView) tabHost.getTabWidget().getChildAt(1).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_list_white));
} else if (TAB_LIST.equals(tabId)) {
ImageView iv = (ImageView) tabHost.getTabWidget().getChildAt(0).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_map_white));
iv = (ImageView) tabHost.getTabWidget().getChildAt(1).findViewById(android.R.id.icon);
iv.setImageDrawable(getResources().getDrawable(R.drawable.tab_list_black));
}
}
});