[Android] Toolbar use in detail (iii)--Source code Analysis

For more information on the Use of toolbar, please visit toolbar use the detailed series

From toolbar use Step by Step Analysis toolbar source code

Approximate structure

API 0. Setting the navigation icon

Mtoolbar.setnavigationicon (R.drawable.ic_actionbar_flow);

The source code is as follows

    public void Setnavigationicon (int resId) {        This.setnavigationicon (this.mTintManager.getDrawable (resId));    }

Setnavigationicon

  public void Setnavigationicon (@Nullable drawable icon) {        if (icon! = null) {            this.ensurenavbuttonview ();            if (this.mNavButtonView.getParent () = = null) {                this.addsystemview (this.mnavbuttonview);                This.updatechildvisibilityforexpandedactionview (This.mnavbuttonview);            }        } else if (This.mnavbuttonview! = null && this.mNavButtonView.getParent ()! = null) {            This.removeview ( This.mnavbuttonview);        }        if (This.mnavbuttonview! = null) {            this.mNavButtonView.setImageDrawable (icon);}    }

First determine if the incoming picture parameter is NULL

• Null to remove the navigation picture.
• Not NULL, create a new ImageView, set its layoutparams, and finally set the ImageView picture as the entry parameter.

Ensurenavbuttonviewensure that the navigation picture is not NULL, and NULL is new and added.

    private void Ensurenavbuttonview () {        if (This.mnavbuttonview = = null) {            This.mnavbuttonview = new ImageButton ( This.getcontext (), (AttributeSet) null, attr.toolbarnavigationbuttonstyle);            Toolbar.layoutparams LP = This.generatedefaultlayoutparams ();            lp.gravity = 8388611 | This.mbuttongravity &;            THIS.MNAVBUTTONVIEW.SETLAYOUTPARAMS (LP);        }    }

Set the navigation icon by layoutparams.gravity

lp.gravity=8388611 set Gravity=start that is the left start position

Gravity is initialized within the toolbar constructor.

      This.mbuttongravity = 48;

48:gravity = Top

&112 = Get the longitudinal position of the gravity

Set the navigation coordinates in the top left position

A detailed description of the gravity
Continue to determine if the parent form is null

Addsystemview

   private void Addsystemview (View v) {        Android.view.ViewGroup.LayoutParams VLP = V.getlayoutparams ();        Toolbar.layoutparams LP;        if (VLP = = null) {            LP = This.generatedefaultlayoutparams ();        } else if (!this.checklayoutparams (VLP)) {            LP = This.generatelayoutparams (VLP);        } else {            LP = (toolbar.layoutparams) VLP;        }        Lp.mviewtype = 1;        This.addview (v, LP);    }

Because toolbar inherits from ViewGroup, when the parent form of the navigation icon is null, the icon is added to the toolbar.Updatechildvisbilityforexpandedactionviewset the navigation icon to visible
API 1.setNavifationOnClickListenerThe source code is as follows

    public void Setnavigationonclicklistener (Onclicklistener listener) {        this.ensurenavbuttonview ();        This.mNavButtonView.setOnClickListener (listener);    }

Ensurenavbuttonview above has made a noteSetonclicklistenerThis.mnavbuttonview is ImageView, this is simply a click on the button to set a listener event. API 2.setTitle

public void Settitle (charsequence title) {        if (! Textutils.isempty (title)) {

<span style= "White-space:pre" ></span>//title NOT null            if (This.mtitletextview = = null) {

<span style= "White-space:pre" ></span>//if the main title TextView does not exist then new                Context context = This.getcontext ();                This.mtitletextview = new TextView (context);                This.mTitleTextView.setSingleLine ();                This.mTitleTextView.setEllipsize (truncateat.end);                if (this.mtitletextappearance! = 0) {                    this.mTitleTextView.setTextAppearance (context, this.mtitletextappearance) ;                }                if (This.mtitletextcolor! = 0) {

<span style= "White-space:pre" ></span>//set Font color                    this.mTitleTextView.setTextColor ( This.mtitletextcolor);                }            }            if (this.mTitleTextView.getParent () = = null) {

<span style= "White-space:pre" ></span>//if the parent form is NULL, add the main caption TextView, with the navigation icon                This.addsystemview ( This.mtitletextview);

<span style= "White-space:pre" ></span>//also updated to visible state                This.updatechildvisibilityforexpandedactionview (This.mtitletextview);            }        } else if (This.mtitletextview! = null && this.mTitleTextView.getParent () = null) {

<span style= "White-space:pre" ></span>//title is null removes the TextView this.removeview of the main header            ( This.mtitletextview);        }        if (This.mtitletextview! = null) {

<span style= "White-space:pre" ></span>//the existence of the main title TextView set the text            This.mTitleTextView.setText (title);        }

<span style= "White-space:pre" ></span>//set current file        This.mtitletext = title;

API 3.setSubTitle, Settitletextcolor, SetsubtitletextcolorThe principle is like Settitle no longer repeat. API 4.inflateMenu

    public void Inflatemenu (int resId) {        this.getmenuinflater (). Inflate (ResId, This.getmenu ());    }

The final call is the Supportmenuinflater.inflate method

   public void Inflate (int menures, menu menu) {        if (!) ( Menu instanceof Supportmenu)) {

<span style= "White-space:pre" ></span>//getmenu method is described below, first remember GetMenu return is Supportmenu implementation class            Super.inflate (menures, menu);        } else {            Xmlresourceparser parser = null;            try {                parser = this.mContext.getResources (). GetLayout (menures);                AttributeSet e = xml.asattributeset (parser);

<span style= "White-space:pre" ></span>//analysis Menu.xml file, add MenuItem this.parsemenu to menu                (parser, E, menu);            } catch (Xmlpullparserexception var9) {                throw new inflateexception ("Error inflating menu XML", VAR9);            } catch (Ioex Ception var10) {                throw new inflateexception ("Error inflating menu XML", var10);            } finally {                if (parser! = Nu ll) {                    parser.close ();}}}}    

GetMenu

    Public Menu GetMenu () {        this.ensuremenu ();        return This.mMenuView.getMenu ();    }

Ensuremenu

  private void Ensuremenu () {        this.ensuremenuview ();        if (this.mMenuView.peekMenu () = = null) {

<span style= "White-space:pre" ></span>//immersive menu is empty            menubuilder menu = (menubuilder) This.mMenuView.getMenu ();            if (This.mexpandedmenupresenter = = null) {

<span style= "White-space:pre" ></span>//Create an immersive menu for each menu item                this.mexpandedmenupresenter = new Toolbar.expandedactionviewmenupresenter (null);            } <span style= "White-space:pre" ></span>//Show menu            this.mMenuView.setExpandedActionViewsExclusive (True );            Menu.addmenupresenter (This.mexpandedmenupresenter, This.mpopupcontext);        }    }

Ensuremenuview

   private void Ensuremenuview () {        if (This.mmenuview = = null) {            This.mmenuview = new Actionmenuview ( This.getcontext ());            This.mMenuView.setPopupTheme (this.mpopuptheme);            This.mMenuView.setOnMenuItemClickListener (This.mmenuviewitemclicklistener);            This.mMenuView.setMenuCallbacks (This.mactionmenupresentercallback, this.mmenubuildercallback);            Toolbar.layoutparams LP = This.generatedefaultlayoutparams ();            lp.gravity = 8388613 | This.mbuttongravity &;            THIS.MMENUVIEW.SETLAYOUTPARAMS (LP);            This.addsystemview (This.mmenuview);        }    }

It is important here that the function is to create a new toolbar menu bar. Implementing the implementation in Actionmenuview,actionmenuview is no longer the scope of this article, as long as you know Actionmenuview inherits Linearlayoutcompat. In fact, the entire toolbar is a linearlayout layout, just above the custom layout.Parsemenu

private void Parsemenu (xmlpullparser parser, AttributeSet attrs, menu menu) throws Xmlpullparserexception, IOException {supportmenuinflater.menustate menustate = new Supportmenuinflater.menustate (m        ENU);        int eventtype = Parser.geteventtype ();        Boolean lookingforendofunknowntag = false;        String unknowntagname = null; String TagName; 

<span style= "White-space:pre" ></span>//find <menu> do {if (EventType = = 2) {                TagName = Parser.getname ();                if (!tagname.equals ("menu")) {throw new RuntimeException ("Expecting menu, got" + tagName);                } EventType = Parser.next ();            Break        } EventType = Parser.next (); } while (EventType! = 1); <span style= "White-space:pre" ></span>//begins to traverse for (Boolean reachedendofmenu = Fals e;!reachedendofmenu; EventType = Parser.next ()) {switch (eventtype) {case 1:throw new RuntimeException ("            Unexpected end of document ");                    Case 2:if (!lookingforendofunknowntag) {tagName = Parser.getname ();                    if (Tagname.equals ("group")) {Menustate.readgroup (attrs); } else if (Tagname.equals ("item")) {</span>

<span style= "White-space:pre" ></span>//add menu item Menustate.readitem (ATTRS);                        } else if (Tagname.equals ("menu")) {submenu submenu = Menustate.addsubmenuitem ();                    This.parsemenu (parser, Attrs, submenu);                        } else {Lookingforendofunknowntag = true;                    Unknowntagname = TagName;            }} break;                Case 3:tagname = Parser.getname (); if (Lookingforendofunknowntag && tagname.equals (unknowntagname)) {Lookingforendofunknowntag = f                    Alse;                Unknowntagname = null;                } else if (Tagname.equals ("group")) {Menustate.resetgroup (); } else if (Tagname.equals ("item")) {if (!menustate.hasaddeditem ()) {if (menustate . itemactionprovider! = null && MenuState.itemActionProvider.hasSubMenu ()) {Menustate.addsubmenuitem ();                        } else {Menustate.additem ();                }}}} else if (Tagname.equals ("menu")) {Reachedendofmenu = true; }            }        }    }

when the analysis is finished, display the MenuItem on the menu.
API 5.setOnMenuItemClickListener

Private final Actionmenuview.onmenuitemclicklistener Mmenuviewitemclicklistener =            New Actionmenuview.onmenuitemclicklistener () {                @Override public                boolean Onmenuitemclick (MenuItem item) {                    IF (Monmenuitemclicklistener! = null) {                        return Monmenuitemclicklistener.onmenuitemclick (item);                    }                    return false;                }            };

The final implementation is in the Actionmenuview.

Welcome to discuss, purely to stimulate.

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

[Android] Toolbar use in detail (iii)--Source code Analysis